[6] In his next bout, Chagaev faced journeyman Val Smith (10–16, 9 KOs) on 14 April 2002 at Hard Rock Hotel and Casino in Las Vegas, Nevada.

Chagaev admitted that his decision to sign the contract with German promoters was caused by the fact that in the United States he had only had four fights in two years and his career there hadn't had any clear direction.

[21][22][23] The bout was placed on the undercard of the event that saw Stipe Drews facing Olivier Beard for the European light heavyweight title and was televised by Eurosport.

Each of the four main-event fights had at least one boxer from a post-Soviet country - him and Muhammadqodir Abdullaev were from Uzbekistan while heavyweight Taras Bidenko and bantamweight Volodymyr Sydorenko were from Ukraine.

[25] Sedreck had a record of 20–21–1, 14 KOs coming into the bout and had only been stopped by Lawrence Clay-Bey, Robert Davis and Oleg Maskaev in his professional career up to that date.

Fields was mostly known for his victories over Shannon Briggs, former IBF world cruiserweight champion Al Cole and Finnish prospect Sami Elovaara and facing numerous boxers from Russia and Belarus.

[25][27] After scoring two knockouts against Alexey Varakin and Wade Lewis inside two rounds each, Chagaev had a rematch with Sedreck Fields four months after their first encounter.

Chagaev continued fighting in a counterpunching manner in the second round, ultimately dropping Fields with a left hook behind the ear and throwing off his equilibrium.

In the build-up, Chagaev's coach Michael Timm complimented his skillset and mindset, including punching power and precision, fearlessness and work ethic.

[51][52] At the beginning of 2006, Chagaev agreed for a rematch against Rob Calloway as a late-minute replacement for Alexander Dimitrenko who had to withdraw due to shoulder injury.

[57][58] Two months after his rematch with Calloway, Chagaev stepped in to face undefeated Ukrainian prospect and former stablemate of his Vladimir Virchis for the WBO and WBA Inter-Continental titles.

[59][64][65] Columnist Troy Ondrizek criticized the US media for not giving enough attention to the matchup: "In just five days a mega-fight between Ruslan Chagaev of Uzbekistan and Vladimir Virchis of Ukraine; will square off in what quite possibly be the best heavyweight fight this year.

[...] I for one would rather see this explosive affair, than a possibly boring twelve round fat man dance between Hasim Rahman and James Toney.

"[86] From the opening bell, both boxers fought at a high pace, with Chagaev attempting to bob and weave while Ruiz tried to come forward, work behind the jab and clinch when in close range.

[94] Chagaev eventually reached agreement to fight WBA world heavyweight champion Nikolai Valuev on 14 April 2007 at the Porsche-Arena in Stuttgart, Germany.

This was Valuev's fourth title defense, previously beating Owen Beck, Monte Barrett and Jameel McCline by stoppage and expressing interest in fighting the then-IBF world heavyweight champion Wladimir Klitschko in a unification showdown in the near future.

Then we all laid flowers at the Monument to the Independence and Humanism, met with children from sports schools, and in the evening a grandiose concert was held at the stadium of the National Bank of Uzbekistan.

"[111] Shortly after winning the title, Chagaev signed the contract to face then-WBO world heavyweight champion Sultan Ibragimov in a unification showdown that would take place in Moscow on 13 October 2007.

On 5 December, Chagaev's first official defence was confirmed to be against Commonwealth heavyweight champion Matt Skelton (21–1, 18 KOs),[120] who was ranked No.15 contender by the WBA at the time of the announcement,[121] on 19 January 2008 at the Burg-Waechter Castello in Düsseldorf.

Skelton's promoter Frank Warren initially wanted the fight to take place in February or March, but Chagaev insisted an earlier date.

[128][129] His next mandatory defense was to be a rematch on 5 July 2008 with Nikolai Valuev, who defeated former WBO champion Sergei Liakhovich by unanimous decision to earn the right.

[133] They were scheduled to fight on 30 May 2009 in Helsinki, Finland at the Hartwall Arena, but Chagaev failed a Finnish medical test, allegedly due to hepatitis.

[138][139] The Ring's pre-fight comparison gave Chagaev the edge on defense, praising him for his fundamentals and footwork, and thought he had a stronger chin.

With over 61,000 fans attending the fight it was the largest audience for a boxing match in Germany since 1939, when Max Schmeling knocked out Adolf Heuser in front of 70,000 people in Stuttgart.

[167] On 15 June 2013, at a press conference in Sofia, Bulgaria, European heavyweight champion Kubrat Pulev (17–0, 9 KOs) stated his plans to fight Chagaev next although details had not been discussed.

[176] In December, a $5 million lawsuit was filed by Oquendo against promoter Terek Box Event seeking damages caused by the agreement to the Federal Court in Manhattan.

These guys pulled a really slick move and tricked me into fighting on July 6 by promising me to increase my purse to $1 million and giving me a rematch at a time when I wasn't mentally right, with my wife and newborn baby being sick and in the hospital.

[178] In May 2015, it was announced that Chagaev would make his first title defense against long time contender WBA #13 Francesco Pianeta (31–1, 17 KOs) on 11 July at the GETEC Arena in Magdeburg, Germany.

[198][199] His parents, Shamil and Zamira Chagaev, are Mishar Tatars from the village of Kalda[198] (located in today's Baryshsky District of Ulyanovsk Oblast, Russia), who moved to the Uzbek SSR in the 1950s.

Around the time shortly after winning the world title, several news reported that Chagaev was having an affair with Gulnara Karimova, daughter of the Uzbek President Islam Karimov.