In 1990, he left California to race for Cradley Heathens in the British League, joining fellow Californian and friend Greg Hancock.

[6] In 1991, Hamill again rode for the Heathens and was named captain[7] and he also made his World Final debut at the Ullevi Stadium in Gothenburg scoring six points.

[6] The 1992 World Championship campaign was cut short for Hamill after breaking his wrist at the Overseas final at Coventry's Brandon stadium, however he was still a major part of the Heathens season, again averaging over eight points.

1993 saw a belated return to Cradley for Hamill who went on to make his second world final appearance in Pocking, Germany which was won by fellow American Sam Ermolenko.

In 1994, Hamill missed out on a place in the World Final in Vojens, Denmark, losing out in run off at the semi-final stage to Greg Hancock.

Hamill had been the main challenger to defending champion Nielsen all season and went into the final round in Vojens needing to beat the Dane by at least ten points.

The odds were stacked in Nielsen's favour riding in his home country, but he could only make the B final, eventually finishing on fourteen points for the evening.

In 1997, Hamill had to leave Cradley Heathens as the team folded, and he joined the Belle Vue Aces in Britain's Elite League.

[8] The defence of his World title started off promisingly with a second place in the opening round in Prague behind fellow American and Team Exide race partner Greg Hancock.

The 1998 season saw another new British Elite League team (the Coventry Bees) and another promising start to his Grand Prix campaign finishing second and then third in the opening two rounds.

Hamill answered the call and joined teammates Greg Hancock, Brent Werner, Billy Janniro and John Cook in Poland.