IPC Grand Prix Final: Jonnie Peacock and Hannah Cockroft win

Britain's Paralympic gold medallists had mixed fortunes at the IPC Grand Prix Final in Birmingham.

Wheelchair racer Hannah Cockroft and sprinter Jonnie Peacock both had easy wins while Aled Davies set a season's best in the discus.

But six-time Paralympic champion David Weir was beaten into second in the T54 1500m by Swiss rival Marcel Hug.

And Richard Whitehead, another London 2012 winner, was disqualified for a false start in the T42 200m.

"It just happens sometimes and you have to move on and go back to the drawing board," Whitehead, 36, told BBC Sport.

"I've had some great successes but sometimes you have some knocks. This is a case where it just didn't go right for me but I'm not going to dwell on it."

Peacock led from start to finish in the T44 100m, winning in an impressive season's best of 10.90 seconds - well clear of Canada's Alister McQueen (11.71) to delight the large crowd at the Alexander Stadium.

The 20-year-old was pleased with his form ahead of next month's World Championships in Lyon.

"I'm pretty happy with that," he said. "It's only my second race of the year and I'm coming into form at the right time.

"I was a bit worried coming here because it's not known as a fast track but I put it together and executed a clean race.

"I wanted to run a decent time coming out here but it is difficult with nobody pushing you.

"The crowd was amazing - every time you compete in front of them and hear the roar it just spurs you on."

Double London gold medallist Cockroft was a dominant winner of the T34 200m in 32.19 seconds, three seconds clear of Amy Siemons of the Netherlands.

David Weir was second to Marcel Hug

"I went out there to practice what I have done in training and see where I am and where the other girls are," said Cockroft, 20.

"I feel in shape and fitter than ever and I know I just have to continue to work on a few things to be ready for the worlds."

Davies, an F42 athlete who was competing in a combined F42/44 class along with less disabled athletes, was thrilled with his throw of 46.88m, enough for fourth place with fellow Briton and F44 athlete Dan Greaves second.

"I knew it would be difficult but it is good to see where I am against the other guys so to have come out with the result and a season's best, I'm chuffed," said Davies, 22.

Weir, who has opted to miss the World Championships to focus on his road racing, found Hug too good, clocking three minutes 28.01 seconds to the Swiss' 3:27.60.

"I can't keep training - I have to do some sort of racing as the intensity isn't really there when you are only training," the 34-year-old said.

"I was quite surprised with how near I got to him and I was pleased with my top-end speed. I raced him in Switzerland recently and we had some good tussles there so it's not bad."

Elsewhere, there were impressive wins for British trio Stephen Miller (men's F32/51 club), Sophie Kamlish (T43/46 100m) and Bethany Woodward (T37 200m) while Northern Ireland's Michael McKillop showed his dominance in the T37 800m.