Usain Bolt produced his season’s-best time in the 100m to canter away with the Monaco Diamond League and suggest he will again be the man to beat going into a major championships.

The Jamaican’s time of 9.95sec will not necessarily have his rivals at next month’s world championships in London trembling but the way he did it, recovering from a typically sluggish start before easing to victory without undue stress or effort, suggests there is a fair bit more in the tank.

Certainly Bolt was an athlete transformed from his poor run in Ostrava last month, when he hobbled through the line in 10.06. He promised his traditional summer time visit to the German doctor Hans-Wilhelm Müller-Wohlfahrt, who uses unconventional techniques such as injecting calves’ blood and using extracts from crests of cockerels into his patients, would fix his back problems. On this evidence there is nothing to suggest otherwise. Once Bolt made his move after 50m there was going to be only one winner.

The American Isiah Young was second in 9.98, with the South African Akani Simbine third in 10.02 – the same time as Britain’s CJ Ujah fourth in the same time.

Britain’s Laura Muir suggested she is fully recovered from a stress fracture in her foot sustained earlier this summer as she ran a personal best of 8min 30.64sec to finish third in the 3,000m behind Hellen Obiri, who obliterated the field to win in 8.23.15.

After the first kilometre Muir was in a group of six athletes who had surged clear of the rest of the field. She decided not to go with Obiri, who had beaten her over a mile in the Anniversary Games earlier this month, and was content to come home in third. Muir said: “The race was fast. I’ve done my outdoor personal best so that’s great. In London I’ll double up in the 1500m and 5,000m.”

Muir’s fellow Scot Eilish McColgan produced the performance of her life to come fourth in 8.31.39 – not only a personal best by 10 seconds but the first time she has bettered her mother Liz’s personal best.

Another Briton, Dina Asher-Smith, made an encouraging step forward in her return from a broken foot as she finished third in the women’s 200m. The 21-year-old, who was fifth at last year’s Olympics, was able to begin sprinting again only last month but a season’s best of 22.89sec suggested she is making rapid progress. However she was a long way behind the Ivory Coast athlete Marie-Josée Ta Lou, whose run of 22.25, suggested she will be among the medal mix come the world championships.

The 400m world record holder Wayde van Niekerk threw up after straining to beat Isaac Makwala. The South African was neck and neck with his rival down the home straight before coming through to win in 43.73 sec, ahead of the Botswanian who ran 43.84.

Another South African, Caster Semenya, also had a tougher race than expected before winning the 800m in 1.55.27, the fastest time of the year. Francine Niyonsaba set a Burundi national record of 1.55.47 in second place with Anjee Wilson, breaking the US record in 1.55.61. The Dutch athlete Sifan Hassan, who will be one of Muir’s main rivals over 1500m at the world championships, set a big personal best of 1.56.81 to come fourth while Britain’s Lynsey Sharp was sixth in 1.58.01.

In the men’s 1500m GB’s Chris O’Hare ran 3:33.61 to break the Scottish record that had stood since 1979.