Daley's involvement in the 10m platform men's final attracted a high of over 6 million to BBC Three at 9.30pm, the channel's best peak of the Olympics.
When Daley switched to BBC One and BBC Olympics 1, the 18-year-old made an even bigger splash, with 15.9m watching him win a medal at 10pm.
Mo Farah capturing a second London 2012 gold, which prompted the runner to perform the 'Mo-bot', was seen by a peak of at least 12.4m at 7.45pm.
With Team GB extending their gold medal tally to 28, 3.78m (31.9%) caught up with all the action with Olympics Tonight from 10.35pm.
Olympics Breakfast, meanwhile, averaged 1.45m (43.3%) for a preview of the penultimate day's events.
BBC One dominated with an all-day share of 36.3% and a primetime share of 39.2%. BBC Three was second with 6.9% and 11.8% respectively - the first time the digital channel has ever beaten ITV to second place in the primetime league tables.
BARB ratings data supplied by Attentional