Michael Phelps roared to victory in the 200m medley in 1min 56.32sec at the Indianapolis Grand Prix, almost two seconds faster than the Olympic season’s previous top time.

Phelps broke his own meet record and crushed Joseph Roebuck’s previous 2012 world-leading time of 1:58.16 set at the British Olympic Trials.

South African Darian Townsend was second in 1:59.28 – eighth-fastest in the world this year, while Phelps’s US rival Ryan Lochte was third in 1:59.37.

For 14-time Olympic gold medallist Phelps, it was further evidence that his preparations for the London Games are at last solidly on track.

It was also a satisfying victory on a night when he may have competed for the last time in an Indianapolis Natatorium pool where he qualified for his first Olympic team in 2000.

“Being able to come back and relive the memories and moments was really special,” Phelps said. “I’m sure my mom has cried a few times already tonight.”

Phelps added the 200m medley title to the 100m butterfly and 400m medley victories he claimed on Thursday and Friday.

Lochte, who won five gold medals at last year’s world championships in Shanghai and beat Phelps in their two head-to-head clashes in 2011, never challenged Phelps in the 200m medley final – which came less than half an hour after Lochte finished tied for third with Denmark’s Mathias Gydesen in the 100m backstroke.

“I think if you ask any backstroker, they’ll basically tell you it’s a leg event and it hurts,” Lochte said.

“But I knew I had to do that double because if I want to do that at the Olympics, I have to learn how do that back-to-back.”

Phelps pronounced himself “very pleased” with his medley time.

“If I’d jumped under 56, I would have been ecstatic,” he said. “But that’s a half-second faster than my time (here) last year. For right now, I’m very pleased.”

Jessica Hardy won the 100m breaststroke in 1:06.12, the fastest time in the world this year giving her a victory by more than two seconds.

Caitlin Leverenz’s victory in the women’s 200m medley in 2:09.71 was second-fastest in the world this year.

Teen phenomenon Missy Franklin won the women’s 100m backstroke in 59.89sec, the second time this season she has broken a minute.