Bradley Wiggins's victory in the men's individual time trial peaked with an audience of 5.94 million (a 48.8% share) at 4pm on BBC One.
This figure does not include the amount of viewers watching online streams or at big-screen events around the UK.
Meanwhile, earlier in the day Helen Glover and Heather Stanning's victory in the rowing brought 4.38m (a 45% share) to BBC One at 12.30pm.
Glover and Stanning became the first female rowers to ever win a gold for Team GB in the Olympics.
Later in the evening, BBC One's primetime coverage of the Games peaked at over 9m (39% share) at 8.15pm during the swimming finals at the Aquatic Centre.
Michael Jamieson won another medal in the pool for Team GB with a silver in the men's 200m breaststroke final with a new British record of 2 minutes 7.40 seconds.
Photo gallery - London 2012 Olympics:
Copyright: Martin Rickett/PA Wire/Press Association Images