Usain Bolt sprinted to a second Diamond League victory within 24 hours at Olympic Stadium on Saturday, one year after the start of the London Games.
Bolt anchored a Jamaican 4x100 relay team to victory in 37.74 seconds, a day after winning the 100 meters in the stadium where he swept three gold medals last year.
"We haven't run a lot of relays together," Bolt said of his teammates. "But just being around each other, we can understand each other and know how fast we are personally. So it worked out very well."
The 26-year-old Bolt led home teammates Mario Forsythe, Kemar Bailey-Cole and Warren Weir ahead of France and Canada.
"I'm the team leader, and I try to keep them focused and give them wisdom," Bolt said.
About 60,000 fans packed into the Olympic Stadium, which temporarily reopened to host the Diamond League. It will be revamped into a multi-sport stadium, which Premier League team West Ham will use in the 2016-17 season.
"It is always beautiful and always wonderful in London, I really enjoy it here," Bolt said. "It is just an extremely great stadium and I am happy."
However, Bolt isn't happy with the British tax laws.
He only returned to London to compete because the government agreed to allow international athletes to compete tax-free at this meet as they did at the London Olympics. Taxes are usually imposed on appearance fees and prize money for non-resident athletes in all sports when competing in Britain.
Bolt said returning to race "depends on what the tax laws say. If they say it's OK, I will be here next year."
A tax exemption is already in place for the Commonwealth Games in Glasgow next year, but Bolt is not committing to competing in the Scottish city.
The government does not appear willing to waive its tax rules whenever it suits an athlete or event officials.
"You have to be a little bit careful about this," Sports Minister Hugh Robertson told The Associated Press. "We have a very straight forward modus operandi with the Treasury whereby whenever we need a tax break for a particular event we make the case, they look at it and they have been very good at granting it as they were for Usain Bolt.
"You have to just realize, though, that all these decisions are taken against the backdrop of the national economy and giving tax breaks to wealthy sports stars when the economy is in the state it is at the moment is something that needs careful decision on a case-by-case basis."