Team GB duo Katherine Grainger and Anna Watkins shatter Olympic record

Katherine Grainger and Anna Watkins have moved a step closer to winning a gold medal after setting a new Olympic best time while they qualified for the final of the women's double scull.

The Great Britain pair are unbeaten in three years and their time of 6min 44.33sec knocked more than five seconds off the previous Olympic best as they comfortably booked their place in Thursday’s semi-final.

Grainger won silver medals in Sydney, Athens and Beijing and, at 36, she finally hopes to reach the top step of the podium in London.Australia won their heat to qualify but they were four seconds slower than the British pair.

Greg Searle’s aim to win a third Olympic medal, 20 years after he won gold in the coxed pair in Barcelona, is also on track after Great Britain held off Olympic champions Canada to move into the final of the men’s eight. The British crew established an early lead which they never lost, resisting the assaults of the boats behind them.

Searle also won a bronze medal at the 1996 Games before quitting the sport in 2001 but the prospect of competing at an Olympic Games on home water tempted him back.

In the men’s eight, Alex Partridge, Matthew Langridge and Richard Egington all have Olympic experience, while Tom Ransley, Mohamed Sbihi, James Foad and Constantine Louloudis are attending their first Games.

Britain and Canada will be joined in Wednesday’s final by the Netherlands and Australia. Germany and the United States qualified for the decisive race automatically by winning their heats.

Great Britain’s women’s quadruple sculls reached their final, also on Wednesday, but not without a scare in their repechage this morning.

At 1,000m the British quartet of Melanie Wilson, Debbie Flood, Frances Houghton and Beth Rodford were last of the six boats but they regained their form in the second half of the race to ensure they advanced to the final behind Australia and United States.