Rocket man Usain Bolt recovered from an awful start to light up the Olympic Stadium once again as he won the 100 metres in 9.85 seconds.
The Jamaican returned to the scene of his triple London 2012 triumph, but was made to sweat before blasting through to take the victory.
The 26-year-old entered the arena atop a missile for his customary lap of honour before the action, but this run hardly fired out a major statement of intent ahead of next month’s World Championships.
It was still his fastest time of the year, though, and in the end he was a comfortable winner, with Mike Rodgers second in 9.98 and Britain’s Dwain Chambers 5th in 10.10.
There was disappointment for the 60,000 crowd as 25-year old James Dasaolu, the second-fastest Briton in history when he ran 9.91 seconds at the British Championships, failed to make the start line.
Bolt said: “I really enjoy competing in London it’s pretty much like competing in Jamaica as there is a lot of Jamaican support.
“For me, you’ve just got to enjoy it; it’s always good to feed off the crowd, work hard, enjoy it, and just go and run as fast as possible.”
Jamaican talent was also in view in the 200m where Warren Weir’s 19.89 seconds prevailed ahead of compatriot Jason Young’s 19.99. Richard Kilty (GB) placed 7th in 20.57.
Olympic champion Kirani James (Grenada) stamped his authority over the 400m field in 44.65 seconds as Tony McQuay (USA) finished best of the rest in 45.09. GB’s Nigel Levine placed 6th (45.98) and Conrad Williams 9th (46.43).
Pre-race favourite Shannon Rowbury (USA), the 2009 world 1,500m bronze medallist, headed the 3,000m field in 8 minutes 41.46 seconds. Eilish McColgan (Dundee Hawkhill) used the race as preparation for her appearance in Moscow where she will contest her main event the 3,000m steeplechase.
Here McColgan came through into ninth in a personal best of 8 minutes 53.66 seconds, carving a sizeable 17 seconds from her previous best over the flat 3,000m.
Newly crowned European junior 1,500m champion Emelia Gorecka (Aldershot FD) finished 10th in a season’s best 8:55.59, with Scottish internationalist Stephanie Twell 13th (8:58.57).
An untidy women’s 1,500m race was won by Mary Kuria (Kenya) in 4 minutes 08.78 seconds, shading Ibtiddam Lakhouad (Morocco) by just 14 hundredths of a second.
Dundee Hawkhill’s Laura Muir finished first British athlete in ninth in 4:10.41, two seconds shy of her personal best while VP Glasgow’s Jo Moultrie, on home leave from New Mexico University, placed 13th in 4:12.42.
Muir’s GB colleague for next month’s World Championships, Marilyn Okoro, faded badly in the 800m, placing fourth in 2 minutes 00.20 seconds. Brenda Martinez (USA) had the strongest finish with a winning 1:58.19.
There was a personal best for Perri Shakes-Drayton over the 400m hurdles,leading until the final 100m to finish second in 53.67 seconds.
Olympic bronze medallist Zuzana Hejnova (Czech Republic) took control in the home straight, clocking a world lead and national record of 53.07.
Shakes-Drayton reflected: “I’ve run my best, what more can you ask for? It’s going well, I’ve got the World Championships coming up, and it’s going to be fun. I did well, it was just that last little bit. I need to get stronger but that will come.
“I’ve got big support from the British people, the turn-out is amazing. It’s really emotional at the minute, I learnt from the experience of last year.”
There was a morale boosting win for the GB women’s 4 x 100m quartet, timed at 42.69 seconds, the fastest by a GB team for 12 years. An All Stars foursome placed second (43.16) and France third (43.46). The GB junior team placed 5th (44.44).
Cuba’s Olympic pole vault silver medallist Yarusley Silva beat Olympic champion and world number one this year Jennifer Suhr (USA) in a high-quality competition.
Silva soared to a Diamond League record 4.83m to take first place ahead of Suhr’s 4.73m.
Ukraine’s Bohdan Bondarenko unsuccessfully attempted a world record 2.47m in the high jump, having successfully cleared 2.38m to defeat Erik Kynard (USA) 2.36m.
Britain’s Olympic bronze medallist Robbie Grabarz placed 4th at 2.28m. Allan Smith, who as a boy developed his career at Pitreavie and Perth Strathtay, finished 7th (2.20m).