Double Olympic champion Mo Farah came through his toughest test of the season to win the men's 5,000m in Birmingham.
Farah impressively won in 13 minutes 14.24 seconds to end a successful day for Britain at the Diamond League.
The 30-year-old's final 200m burst pushed Ethiopian pair Yenew Alamirew and Hagos Gebrhiwet into second and third respectively.
There were also victories for Britons Perri Shakes-Drayton, Jessica Judd and Christine Ohuruogu.
But Farah stole the show with a tactically astute run to ease doubts over his form ahead of the World Championships in August.
"The young guys wanted to beat me, I'm the guy to beat," Farah told BBC Sport after getting the better of the highly fancied Alamirew and Gebrhiwet, two of the fastest 5,000m runners in the world this year.
"The pace was slow and the conditions weren't great. It was very windy.
"[The other runners] were working as a team, but you've got to hold your form and make sure you've got something else left."
Perri Shakes-Drayton's promising start to the season continued as she ran a season's best 53.82 secs in the women's 400m hurdles.
The Londoner comfortably finished ahead of Scotland's Eilidh Child (54.22 secs) in second, while another Briton, 23-year-old Meghan Beesley (55.73 secs), was fourth.
"It wasn't the perfect race," said Shakes-Drayton. "It's always nice to peak as you get close to a championship. We need to stay fit and healthy."
Jessica Judd, winner of the 800m at last week's European Team Championships, crossed the line in first place to raucous cheers.
"I'm so happy," said the 18-year-old after achieving a personal best of 1:59.85 to beat compatriot Marilyn Okoro (2:00.76) and Ethiopia's Fantu Magiso (2:01.12) with ease.
"Last year people didn't know who I was. It was nice to get a cheer at the start line."
A trademark late surge from Christine Ohuruogu (50.63 secs) saw the Briton dip ahead of the in-form 2011 world champion Amantle Montsho in the women's 400m.
Britain's Olympic champion Greg Rutherford (8.11m) and his compatriot Chris Tomlinson (7.97m) had to settle for second and third respectively in the men's long jump as Russia's Aleksandr Menkov won the competition with a leap of 8.27m.
There was a surprise second place for Welshman Rhys Williams in the men's 400m hurdles.
Williams, one of a number of senior athletes to lose National Lottery funding after London 2012, clocked 48.93 secs, finishing behind world silver medallist Javier Culson.
Another Welshman, reigning world champion Dai Greene (49.55 secs) struggled in fifth, while out-of-sorts Olympic champion Felix Sanchez (49.68) was seventh.
In the men's 100m, James Dasaolu equalled the fourth fastest 100m run by a Briton as he produced a personal best 10.03 secs to finish second in a race won by Jamaica's Nesta Carter in 9.99 secs.
Kim Collins, at 37 the oldest athlete competing in Birmingham, was third (10.06), while Britain's James Ellington ran a personal best 10.17 in sixth.
A season's best 2.31m from Britain's Robbie Grabarz in the men's high jump was only enough for third spot, ahead of compatriot Tom Parsons (2.25m) in fourth.
Laura Weightman (4:06.22) was the leading Briton in the women's 1500m, finishing fourth in a race easily won by Sweden's Abeba Aregawi (4:03.70).
Hannah England (4:07.23) was seventh, while Laura Muir and Lisa Dobriskey were eighth and 10th respectively.
Both Shelly-Ann Fraser-Pryce and Carmelita Jeter were overshadowed in the women's 200m by Nigeria's Blessing Okagbare.
Okagbare's time of 22.55 secs pushed Olympic 100m gold medallist Fraser-Pryce (22.72) into second, while 100m world champion Jeter (23.36) was a distant seventh. Britain's Anyika Onuora (23.13) ran home in fifth.
The men's triple jump was won by reigning Olympic and world champion Christian Taylor. A season's best 17.66m leap from the United States athlete was enough to relegate Frenchman Teddy Tamgho (17.47m) to second. Britain's Nathan Douglas was fourth with a season's best 16.70m.
America's Dawn Harper-Nelson won the women's 100m hurdles in 12.64 seconds, finishing ahead of compatriot Kellie Wells (12.67) and Britain's Tiffany Porter, who ran a season's best 12.72 in third.
Reigning world and Olympic champion Sally Pearson, troubled by a hamstring problem during the Australian domestic season, was fourth in 12.73.
Elsewhere, Ryan Brathwaite of Barbados led from start to finish to win the men's 110m hurdles in 13.13 secs. Olympic champion Aries Merritt had to settle for second.
Ethiopia's Aman Wote won the men's 1500m in 3:35.99, while Kenya's Milcah Chemos broke the meeting record to secure the women's 3,000m steeplechase in 9:17.43.