[19][24] He finished ninth at the Golden Gala in Rome with a slow time of 10.41 s and was seventh in a tame 10.30 s at the London Grand Prix, results that led him to consider quitting the season altogether.

[26] Victory against in-form world record holder Maurice Greene in Gateshead raised Chambers' confidence and he stated his aim to take home a medal from the Games.

He easily qualified through the heat stages and achieved a season's best of 10.08 s in the 100 m final finishing fourth behind Greene, Ato Boldon and Obadele Thompson.

[13][32][33] Chambers ran with consistency in the summer of 2001: he won at the Seville Grand Prix in 10.01 s and finished third in ten seconds flat at the Athletissima meet.

[13][37][38] In an interview with Tom Fordyce, Chambers stated that Maurice Greene's strong presence and mind games undermined the competition both physically and mentally.

[42] Chambers ended his season at the 2001 Goodwill Games in Brisbane, and finished in first place in the absence of an injured Greene, who commentated on his European rival's victory.

[44] Frustrated by the distance between himself and the top sprinters, Chambers decided to relocate to California to work with Ukrainian coach Remi Korchemny and nutritionist Victor Conte.

[51][52] Victories over Maurice Greene followed at Oslo's IAAF Golden League meeting and in Sheffield with a wind-assisted 9.95 s.[x 1][49][53] He was the favourite for the 2002 Commonwealth Games, but Chambers faced stiff competition from British newcomer Mark Lewis-Francis who was finishing fractions of a second behind him.

[62] Chambers began the 2003 season with a grandiose statement – namely that he would lower the 100 m record to 9.65 s.[63] After recovering from a minor injury he suffered in January,[64] Despite claims he could also beat the 60 m indoor record, his form was poor and he failed to pass the heats at the 2003 British Grand Prix, finishing fourth in a time of 6.68 s.[x 1][65] He was beaten by Mark Lewis-Francis by a hundredth of a second at the trials for the IAAF World Indoor Championships, narrowly missing out on selection with a time of 6.59 s.[x 1][66] Chambers announced that he was to part with trainer Mike McFarlane in favour of a permanent relationship with Ukrainian coach Remi Korchemny.

[x 1][68][69] Chambers beat Montgomery in Glasgow in June, running a stadium record of 10.15 s into a headwind,[x 1][70] and qualified for the World Championships by winning the AAA trials.

[x 1][71] His season's best came under unusual circumstances at the British Grand Prix – due to a system malfunction he was initially timed by hand at dead on ten seconds, which was amended to 9.96 s after video evidence was consulted.

[x 1][72] Chambers squandered his anchoring lead in the 4×100 m relay, allowing Joshua J. Johnson of the United States team to beat him to the finish line.

[29][45][74][75] The United States Anti-Doping Agency (USADA) were investigating the Bay Area Laboratory Co-operative (BALCO); the workplace of both Chambers' coach Remi Korchemny, and nutritionist Victor Conte.

[13][96] Ironically, with the exception of the 9.87 s he clocked to equal Linford Christie's British record in Paris in 2002, Chambers was a consistently quicker athlete before he moved to San Francisco that year and became entangled in the drugs net spun by Victor Conte, and the Bay Area Lab Co-operative.

[97] On his return to international competition his times were significantly worse than he achieved prior to drug use: in the 100 m final at the 2006 European Championships, Chambers ran a sub-par 10.24 s and finished in fifth place.

[100][101] After the competition, Chambers again expressed an interest in switching to American football, and completed a week-long NFL Europa training camp in Cologne that November.

[109] Chambers reflected on drug use in athletics in an interview with Olympic gold medallist Sir Matthew Pinsent for the BBC's Inside Sport programme.

[109] Chambers was roundly condemned for his comments in the interview by both the press and his former colleagues in the athletics world, including Sir Steve Redgrave, Mo Farah,[111] and Sebastian Coe.

[119] At the World Indoor Championships 60 metres final, Chambers won a silver medal and recorded a new personal best of 6.54 s to take second behind Olusoji Fasuba.

To return to the track Chambers had to rely on the money he received from his partner, Leonie Daley, a civil servant whom he met at the Miss Jamaica UK competition.

[129] Chambers' return to athletics took an unusual turn when he confirmed in March 2008 that he had joined English rugby league team Castleford Tigers on trial;[130][131] a move which surprised and angered in equal measure given the fact he had never played the sport before.

[163] The Olympic ban remained in place, however, and London 2012 chairman Sebastian Coe said: "I am clear cut on the Chambers case – I don't think there is room for drugs cheats in sport".

[168][169] British head coach van Commenee stated that Chambers had undergone vigorous testing and that his performance sent "a message that you can win and break European records in the proper way.

The following year, he began by focusing on the 2010 IAAF World Indoor Championships, and he won the 60 m at the UK trials in 6.50 seconds (a time only he had bettered in the previous two seasons).

[192] Lemaitre and Chambers were seen as the only gold medal contenders for the 100 m final at the European Athletics Championships, but the event defied expectations in terms of times and placings.

[195] At the 2011 European Athletics Indoor Championships the following month he was beaten to the line by Obikwelu, although he was pleased with the silver medal as he had changed his training to focus towards the 100 m for that season.

[199] He won his fifth national title in the 60 m in 2012 with a season's best of 6.58 m.[200] A third consecutive podium finish came at the 2012 IAAF World Indoor Championships, where he pipped Trell Kimmons to the bronze medal.

[202] Chambers ran a 150 m-straight best of 15.27 seconds at the Great City Games in May then won the 100 m Olympic trial race, holding off emerging teenager Adam Gemili.

[203][204] His absence from the major track circuit came to an end with a run at the Diamond League London Grand Prix, although he did not achieve the Olympic "A" standard time there.

He founded the Dwain Chambers Performance Academy,[218] which aims to provide all round coaching for the next generation of sporting stars and is open for young athletes between 9 and 21.