Cracknell (second right) was pleased to be back in action

Germany and Canada, the current world champions, also won their heats ahead of Saturday's final.

Cracknell, who had been suffering from a stress fracture of the ribs, said he was pleased to be competing again.

"The four has really moved on in the last couple of weeks and I've had to catch up but in the last few days I've begun to feel part of it," he said.

Meanwhile, Britain's reigning world pair champions, Cath Bishop and Katherine Grainger, won their heat to progress to Saturday's final.

And Sarah Winckless had a challenging morning.

She competed and won with Elise Laverick in the heats of the women's double scull and then raced as a substitute in the women's quadruple scull after the withdrawal through illness of Frances Houghton.

"We have had a very encouraging day", said British Performance Director David Tanner.

"Our lead boat had an excellent row and many crews have moved on since the world cup in Poznan three weeks ago".