Powell (left) made an explosive start to beat Gay (right)
Jamaica's Asafa Powell stormed to victory over American Tyson Gay to win the 100m at the final Golden League meeting of the season in Brussels.
Gay, the world 100m silver medallist, failed to capitalise on the absence of world record holder Usain Bolt, who cruised to victory in the 200m.
Powell ran 9.90 seconds, while Bolt ran 19.57, the fourth fastest 200m ever.
Sanya Richards, Kenenisa Bekele and Yelena Isinbayeva all won their events to share the $1m Golden League prize.
At last month's worlds in Berlin, Powell came home third behind Bolt and Gay but the former world record holder was too strong at the King Baudouin Stadium.
"I ran a good race - the start especially was good," said Powell.
"I even set off too quickly - I gave it a lot over the first 20-30m, then I kept it going. This new track is really fast. Unfortunately, the rain which fell just before the race affected us."
Gay said, who clocked 10.00, said: "I just got my butt kicked. I completely messed up my start - and that made it really difficult to get into my stride."
Triple Olympic and world champion Bolt chose to concentrate on the 200m and delighted the capacity crowd with another scintillating performance.
The fans always expect something extra from me and I was very surprised by the energy they gave me
He was already clear of the field at the bend, and eased off to post a phenomenal time in wet conditions. American Wallace Spearmon was second in 20.19.
"I am very tired, my body was telling me to slow down. I was fatigued in the last 20-30m," said Bolt.
"But the crowd gave me that extra push - the fans always expect something extra from me and I was very surprised by the energy they gave me.
"I enjoy to do the show, always, and I knew that as it is a new track it would be fast."
Bolt's time was the fourth fastest ever, decimating the meeting record of 19.79, set by Gay three years ago.
Only Michael Johnson, whose world record of 19.32 Bolt broke by two-hundredths-of-a-second at last year's Beijing Olympic and then lowered to 19.19 in the recent World Championships, has run faster.
Richards, Bekele and Isinbayeva claimed a share of the £610,700 pot by winning their events at all six of the Golden League meetings this season.
American Richards won the women's 400m in 48.83 with Britain's Olympic champion Christine Ohuruogu was second in 50.43.
Isinbayeva, who failed to defend her world title in Berlin last month, won the pole vault with a first-time clearance of 4.70m to maintain her perfect Golden League record.
Two years ago, the Russian won half of the jackpot, sharing it with Richards.
Ethiopia's Bekele, who claimed an unprecedented long-distance double with golds in the 5,000 and 10,000m in Berlin, rounded off a spectacular season with victory in the 5,000m.
Carmelita Jeter of the USA sprung a surprise in the women's 100m, beating world champion Shelly-Ann Fraser in a time of 10.88.
A team from Kenya broke the world record in the rarely run 4 x 1,500m relay with a time of 14 minutes 36 seconds. The time was almost two seconds better than the previous best set by a West German team in 1977.
An England quartet of Andy Baddeley, Ricky Stevenson, Nick McCormick and Mark Draper smashed the 30-year-old UK 4x1,500m relay record in finishing fifth in 14:54.57 to erase the previous mark by two seconds.
Britain's Michael Bingham finished third in the 400m behind American Jeremy Wariner, who won in 44.94.
Bingham finished in 45.70, three-hundredths-of-a-second ahead of Ireland's David Gillick, with Martin Rooney clocking 45.83 in fourth.
Simeon Williamson had to settle for eighth in the 100m, while Kate Dennison finished sixth in the pole vault.
The meeting in Brussels marked the end of 12 seasons of the Golden League. Next year, world governing body IAAF will launch the Diamond League, a 14-city tour also including events in Asia and the United States.