Mo Farah ran the fastest 5,000m of 2016 to storm to victory in his last race before the Rio Olympics at the Anniversary Games in London.
The 33-year-old totally dominated on the same track where he won 5,000m and 10,000m Olympic gold in 2012, crossing the line in 12 minutes 59.29 seconds.
Fellow Briton Andrew Butchart was second, more than 15 seconds slower, with American Bernard Lagat third.
"I just wanted to go for it. It's great to win before Rio," said Farah.
"It wasn't that quick but this track means so much to me.
"I am in good shape and I just have to keep my feet on the ground. In two weeks anything could happen - I've just got to stay cool."
Farah - running in his first competitive 5,000m race of the year - was one of five final-day British wins as athletes intensified their preparations for the Rio Games, which get under way on 5 August.
There was victory for Katarina Johnson-Thompson in the women's long jump with a season's best effort of 6.84m, eight centimetres short of her personal record.
Fellow Briton and world silver medallist Shara Proctor was second with a season's best of 6.80m, but there was disappointment for Jessica Ennis-Hill.
The world and Olympic heptathlon champion, who'll be competing against Johnson-Thompson in that event in Rio, finished in a disappointing seventh with a jump of 6.19m, more than 40 centimetres below her best of the season.
"It's exactly what I wanted before Rio," Johnson-Thompson told BBC Sport. "It gives me confidence I can get on the board there.
"But Jess is such a strong competitor I know she'll do better than that at the Olympics. Gold will not be an easy job for anyone and I've got to step up to the competition."
There was a British one-two in the men's 4x100m relay, with the A and B teams pushing each other all the way to the line, well clear of the rest of the field.
Britain's A quartet of James Dasaolu, James Elllington, CJ Ujah and Adam Gemili came home in 37.78 seconds - a world-leading time for the year and only 0.05 seconds away from the British record. The B team finished just 0.03 seconds behind.
Matthew Hudson-Smith's time of 45.03 proved enough for victory in the men's 400m after fellow Briton Martyn Rooney was disqualified for a false start.
American Molly Ludlow had looked set for victory in the women's 800m before Shelayna Oskan-Clarke stole in with a season's best time of one minute 59.46 seconds, with fellow Briton Lynsey Sharp claiming second as Ludlow slipped to third.
But in the men's 110m hurdles there was disappointment for Andrew Pozzi, who won his heat comfortably with a personal best but was forced to withdraw from the final after suffering cramp in the warm-up.
Lawrence Clarke was then disqualified for a false start, leaving David Omoregie as the sole Briton. His time of 13.64 was only good enough for fifth as Frenchman Dimitri Bascou claimed an emphatic victory in 13.20.
Britain's Dina-Asher Smith was fourth in the women's 100m, won by Marie-Josee Ta Lou of the Ivory Coast with a personal best of 10.96 as Jamaica's Olympic champion Shelly-Ann Fraser-Pryce came third.
And in the women's 200m, world champion Dafne Schippers of Netherlands was the comfortable winner, with Britain's Jodie Williams fifth.
'I'm in form but what about my rivals?'
Mo Farah on BBC Radio 5 live: "I know I am in form, training has been going well, but how are my rivals doing?
"It's not as easy as me saying: 'I've run a decent time, I should win in Rio.' It's not like that.
"I will try my best not to have anyone to beat me but anything can happen.
"It's easier to win first time but harder to defend because people have had four years to work out how to beat me."
Four-time Olympic gold medallist Michael Johnson on BBC One:
"It gets more challenging for Farah now he's older. He's dominated but the Kenyans are trying to figure out how to beat him.
"They are coming up with a plan and hoping to catch him on an off-day. It'll be fun because it'll make it even more competitive."
Two-time world 110m hurdles champion Colin Jackson on BBC One:
"My pick for British performance of the weekend is Katarina Johnson-Thompson. She had a busy two days but had two great competitions.
"She had a personal best in the high jump on Friday and then to return today to win the long jump with a personal best was brilliant."