Great Britain took their gold medal tally to 10 with two rowing victories putting them third in the overall medals table at the London Olympics, BBC Sport said.
Britain’s medal count is now 10 golds, seven silvers and eight bronzes.
The first medal came as the men’s four of Andy Triggs Hodge, Pete Reed, Andy Gregory and Tom James led from the start to win gold.
Just 20 minutes later the women’s lightweight double sculls team of Sophie Hosking and Katherine Copeland did the same.
The men’s lightweight double sculls duo of Zac Purchase and Mark Hunter then finished second following a restart after their seat broke.
In rowing, Britain have won four golds, two silvers and three bronzes – a new record for an Olympic regatta.
At the Olympic Stadium, Ennis leapt 6.48m in the long jump and then threw a personal best of 47.49m in her weakest event – the javelin. That leaves her on 5,971 points – 188 points ahead of Lithuanian Austra Skujyte. World champion Tatyana Chernova is in sixth, 314 points down.
On the track, men’s 100m champion Usain Bolt reached the semi-finals, strolling his heat in 10.09 seconds.
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American Ryan Bailey qualified fastest in 9.88, with world champion Yohan Blake running 10 seconds exactly.
British hope Adam Gemili – who was playing non-league football as recently as January – also qualified in 10.11, behind Jamaica’s Asafa Powell, who ran 10.04. Briton Dwain Chambers is through in 10.02.
Britain’s track cyclists are favourites to win their fourth gold at the London Velodrome as Dani King, Laura Trott and Jo Rowsell go in the women’s team pursuit final. The trio broke the world record in qualifying.
Also at the Velodrome, Jason Kenny set a new Olympic record in qualifying for the men’s individual sprint.
Andy Murray , who is already through to the men’s singles tennis final, reached the mixed doubles semi-finals with playing partner Laura Robson.
China and the USA lead the overall medals table.