GB four impress in semi

The Great Britain lightweight men's four rowing crew underlined their Olympic gold medal potential with a commanding semi-final victory at Eton Dorney.

Richard and Peter Chambers, Chris Bartley and Rob Williams unleashed a powerful sprint for the line to surge clear of Switzerland in the final 500 metres.

The British crew won in five minutes 59.68 seconds, just quicker than the time posted by chief gold medal rivals Denmark in winning the second semi-final.

Britain's tally of Olympic finalists has now risen to seven, with the women's eight and the men's double scull of Bill Lucas and Sam Townsend both progressing.

The underperforming women's eight, bronze medallists at the World Championships last year, claimed the last available place in Thursday's final by finishing fourth in the repechage.

Townsend and Lucas finished third in their semi-final behind the Slovenian crew, who were Olympic champions 12 years ago, and Lithuania.

There was a shock in the first heat with reigning Olympic champions Australia and world silver medallists Germany failing to qualify.

Alan Campbell moved smoothly into the semi-finals of the single sculls with a length victory over Germany's Marcel Hacker to underline his own podium credentials.

Campbell, a bronze medallist at the 2011 World Championships, controlled the race after establishing an early lead over the veteran German.

Competition is fierce in the single scull, with Hacker a recent gold medallist at the Munich World Cup and so to qualify with a race victory was a confidence boost for Campbell.