Konstantin Borisovich "Kostya" Tszyu ( ; ; born 19 September 1969) is a Russian-Australian former professional boxer who competed from 1992 to 2005. He held multiple world championships in the light-welterweight division, including the undisputed and lineal championships between 2001 and 2005. Tszyu was an exceptional all-around boxer-puncher who relied heavily on accuracy, timing, and carried formidable punching power; he is often regarded as one of the hardest-punching light-welterweights in the division's history, and one of the greatest light-welterweights of all time.Ricky Hatton recalls Kostya Tszyu battle 10 years later – Ring TV . Ringtv.craveonline.com (2015-06-03). Retrieved on 2016-06-03.

As an amateur, Tszyu represented the Soviet Union, winning a bronze medal in the lightweight division at the 1989 World Championships, and gold in the light-welterweight division at the 1991 World Championships. He also won consecutive gold medals at the 1989 and 1991 European Championships.

In 1995, Tszyu won his first of many professional world championships at light-welterweight—the International Boxing Federation (IBF) title—by defeating Jake Rodríguez. Five successful defences were made until an upset loss to Vince Phillips in 1997, which was Tszyu's first professional defeat. He would spend the next eight years undefeated, winning the vacant World Boxing Council (WBC) title in 1999 and the World Boxing Association (WBA) (Super version) title in 2001. Tszyu scored arguably his most famous win that year, when he knocked out Zab Judah to reclaim the IBF title, as well as the vacant Ring magazine and lineal titles, thus becoming the first undisputed light-welterweight champion in over 30 years. In 2005, in what would be his final fight, Tszyu was stopped by Ricky Hatton.

Tszyu is considered by many in Australia to be a national sports hero.Ricky Hatton vs. Kostya Tszyu. Victoria Warehouse (2015-06-09). Retrieved on 2016-06-03. In The Ring'''s March 2010 issue, Tszyu was ranked as the number one light-welterweight of the 2000s decade. In December 2010, he was inducted into the International Boxing Hall of Fame for the Class of 2011. From 2012 to 2013 he coached professional boxers Alexander Povetkin, Denis Lebedev and Khabib Allakhverdiev.Костя Дзю начнет работать с Александром Поветкиным . 46tv.ru (5 June 2013) In 2023, his son Tim Tszyu won the World Boxing Organization (WBO) junior-middleweight title.

Early life Tszyu was born in Serov, a town near the Ural Mountains, in the former Soviet Union to a father of Korean and Mongol descent and a Russian mother. Tszyu's father was a fitter in a metal factory, whereas his mother was a nurse.

Amateur career As a child, Kostya was hyperactive, so his father decided to take him to a boxing gym, where he would channel that energy by fighting older boys. He impressed the Soviet amateur team coaches and he was sent to the Soviet Union's amateur boxing travelling training camps, where he visited more than 30 countries while training and fighting in tournaments. He trained with that group 250 days a year, and won various tournaments, such as amateur boxing's world championships. At the Cuban world championship tournament in 1987, he came in second place, and at the 1988 Summer Olympics, he lost in the third round.

Tszyu was a member of the Soviet Army, but since he was selected as an elite athlete, he was not required to serve the ordinary duty. He fought at the world championships once again, in Moscow in 1989, where he came in third place.

In 1991, he went again to the amateur world championships, this time held in Sydney. This was a trip that would change his life forever. Not only was the third time his charm, but he felt enchanted with the sights of Sydney and its people, and decided he wanted to live in Australia. Following the collapse of the Soviet Union in 1991, early the next year, Tszyu emigrated to Australia with his girlfriend, where they married in 1993 and became Australian citizens, settling in Sans Souci, Sydney. Before marrying her, though, Tszyu had already turned professional, beating Darrell Hiles by a knockout in one round on 1 March 1992, at Melbourne.

Highlights

Schwerin Junior Open (57 kg), Schwerin, East Germany, April 1986: Finals: Lost to Jörg Heidenreich (East Germany) by unanimous decision, 5–0 European Junior Championships (57 kg), Copenhagen, Denmark, September 1986: 1/8: Defeated Manuel Moreno (Spain) by unanimous decision, 5–0 1/4: Defeated Santo Serio (Italy) by unanimous decision, 5–0 1/2: Defeated Daniel Dumitrescu (Romania) by unanimous decision, 5–0 Finals: Defeated Fared Cheklat (France) by unanimous decision, 5–0 Soviet International Junior Tournament (60 kg), Tbilisi, Georgian SSR, December 1986: Finals: Defeated Nikolay Dzhachvadze (Georgian SSR) RSC 3 World Junior Championships (60 kg), Havana, Cuba, July 1987: 1/4: Defeated D. Boyev (Bulgaria) RSC 3 1/2: Defeated Eduardo Rivas (Panama) KO 2 Finals: Lost to Juan Hernández Sierra (Cuba) by majority decision, 1–4 Soviet International Tournament (60 kg), Leningrad, Soviet Union, December 1987: Finals: Defeated Serik Nurkazov (Kazakh SSR) by unanimous decision, 5–0 Soviet National Championships (60 kg), Tashkent, Uzbek SSR, January 1988: 1/16: Defeated Adylkan Bekbolotov (Kyrgyz SSR) by unanimous decision, 5–0 1/8: Defeated Vladimir Kravtsov (RSFSR) by unanimous decision, 5–0 1/4: Defeated Serik Nurkazov (Kazakh SSR) by unanimous decision, 5–0 1/2: Defeated Samson Khachatryan (Armenian SSR) by unanimous decision, 5–0 Finals: Lost to Orzubek Nazarov (Kyrgyz SSR) by split decision, 2–3 USA–USSR Duals (60 kg), Moscow, Soviet Union, March 1988: Defeated Donald Stokes (United States) on points, 16–8 Pre-Olympic Tournament (60 kg), Seoul, South Korea, March 1988: Finals: Defeated Andreas Zülow (East Germany) by majority decision, 4–1 Soviet International Tournament (60 kg), Leningrad, Soviet Union, June 1988: 1/2: Lost to Julio González (Cuba) on points Summer Olympics (60 kg), Seoul, South Korea, September 1988: 1/32: Defeated Leopoldo Cantancio (Philippines) KO 1 1/16: Defeated Sean Knight (Barbados) RSCH 1 1/8: Lost to Andreas Zülow (East Germany) by split decision, 2–3 Soviet National Championships (60 kg), Frunze, Kyrgyz SSR, January 1989: 1/2: Defeated Yevgeny Burchak (RSFSR) Finals: Defeated Orzubek Nazarov (Kyrgyz SSR) RSC 3 Golden Belt Tournament (60 kg), Bucharest, Romania, April 1989: (no data available) European Championships (60 kg), Athens, Greece, May–June 1989: 1/8: Defeated Andreas Zülow (East Germany) by split decision, 3–2 1/4: Defeated George Cramne (Sweden) by unanimous decision, 5–0 1/2: Defeated Dave Anderson (Scotland) by walkover Finals: Defeated Daniel Dumitrescu (Romania) by majority decision, 4–1

World Championships (60 kg), Moscow, Soviet Union, September 1989: 1/8: Defeated Mark Ramsey (England) on points, 22–3 1/4: Defeated Bo Espensen (Denmark) RSCH 2 1/2: Lost to Andreas Zülow (East Germany) on points, 14–17 Bulgaria–Europe Duals (60 kg), Varna, Bulgaria, November 1989: Defeated Emil Chuprenski (Bulgaria) RET 2 Mayor's Cup (63,5 kg), Manila, Philippines, November 1989: 1/4: Defeated Nelson Factoranan (Philippines) KO 1 1/2: Defeated Andreas Otto (East Germany) by decision Finals: Defeated Shannan Taylor (Australia) by unanimous decision, 5–0 King's Cup (63,5 kg), Bangkok, Thailand, February 1990: Finals: Defeated Andreas Zülow (East Germany) on points, 17–7 USA–USSR Duals (63,5 kg), Moscow, Soviet Union, April 1990: Defeated Terron Millett (United States) by unanimous decision, 3–0 Soviet National Championships (63,5 kg), Lutsk, Ukrainian SSR, April 1990: 1/2: Defeated Vasily Kirilov (RSFSR) Finals: Defeated Aleksandr Banin (Belarus SSR) by decision Goodwill Games (63,5 kg), Seattle, Washington, July 1990: 1/4: Defeated Vukašin Dobrašinović (Yugoslavia) by walkover 1/2: Defeated Terron Millett (United States) by unanimous decision, 5–0 Finals: Defeated Aleksandr Banin (Soviet Union) by unanimous decision, 5–0 Swedish International Tournament (67 kg), Göteborg, Sweden, December 1990: Finals: Defeated Sergey Pogosov (Soviet Union) RSC 3 Soviet National Championships (63,5 kg), Kazan, Tatar SSR, February 1991: 1/2: Defeated Vasily Kirilov (RSFSR) Finals: Defeated Oleg Nikolayev (RSFSR) by unanimous decision, 5–0 USA–USSR Duals (63,5 kg), Spokane, Washington, March 1991: Lost to Vernon Forrest (United States) by split decision, 2–3 European Championships (63,5 kg), Göteborg, Sweden, May 1991: 1/16: Defeated James Pender (Scotland) on points, 21–0 1/8: Defeated Darren McCarrick (England) RSC 1 1/4: Defeated Attila Arslan (Turkey) RSC 2 1/2: Defeated Vukašin Dobrašinović (Yugoslavia) on points, 26–6 Finals: Defeated Andreas Zülow (Germany) on points, 33–11 World Championships (63,5 kg), Sydney, Australia, November 1991: 1/8: Defeated Albertano Caballero (Mexico) RSC 2 1/4: Defeated Aníbal Acevedo (Puerto Rico) on points, 29–10 1/2: Defeated Moses James (Nigeria) on points, 25–4 Finals: Defeated Vernon Forrest (United States) on points, 32–9

1992 Olympics He was the only Soviet boxer to win a gold medal at the 1991 World Championships in Sydney. Immediately at the Championships he was approached by local boxing promoters, deciding to pass up the 1992 Summer Olympics in favor of a professional career. A week later he signed with Australian promoter Bill Mordey as his manager and Johnny Lewis as his trainer in Sydney. Tszyu finished his amateur career with 270 fights, 259 wins, 11 losses, no stoppages and no draws. His professional debut was scheduled to take place in January 1992. Mordey described Tszyu as the best boxer he had seen in the past decade.Boxing: Tszyu to Australia. The New York Times, 29 November 1991, p. 12.

Professional career Tszyu started raising his quality of opposition almost immediately. In his fourth professional bout, he met the former WBC Featherweight Champion Juan Laporte, decisioning him over ten rounds. In his sixth bout, he beat contender Sammy Fuentes by a knockout in the first. Fuentes would go on to win a world title years after being handily beaten by Tszyu in 1993, Steve Larrimore, Larry La Crousiere and Robert Rivera, went to Australia to fight Tszyu, and none lasted more than two rounds. The only man to last more than two rounds with Tszyu in 1993 was Livingstone Bramble, a former World Lightweight Champion, who lost by decision to Tszyu at Newcastle, New South Wales.

In 1994, Héctor López, Angel Hernandez (who had just come off of a loss after challenging Julio César Chávez for the WBC belt), and Pedro Chinito Sanchez from the Dominican Republic tried to beat Tszyu, but Tszyu beat Lopez by a decision in ten, Hernandez by a knockout in seven, and Sanchez by a knockout in four. After the win against Sanchez, Tszyu was ranked number one in the light welterweight division.

WBC light-welterweight champion In 1995, he received his first world title shot when he fought IBF Light Welterweight Champion Jake Rodríguez at Las Vegas, Nevada. Tszyu became world champion by knocking Rodriguez out in the sixth round. He then defended the world title, beating former Super Featherweight and Light Welterweight World Champion Roger Mayweather by a decision in 12, Hugo Pineda by a knockout in 11, Cory Johnson by a knockout in four and Jan Bergman by a knockout in six. After this string of defences, Tszyu became a highly touted world Champion by many boxing magazines, and many articles about him appeared on The Ring, KO Magazine and other American boxing publications.

Title defences