Pat Evans's final day on the Square attracted 9.76m (36%) between 7pm and 8.10pm, while 736k (6.6%) sought out the landmark episode at the unusual time of 11.20pm on BBC Three.
Following EastEnders, the second series of Sherlock kicked off with an impressive 8.75m (30.9%), after which a new Absolutely Fabulous special capped a fruitful night for BBC One with 7.12m (28.3%) at 9.40pm.
Harry Potter and the Half Blood Prince appealed to just 3.45m (12.5%) for ITV1 (+1: 522k/2%), making the screening by far the least-watched terrestrial premiere of the franchise.
BBC Two's Great Barrier Reef interested 3.02m (10.6%) in the 8pm hour, before the channel's audience dropped to 2.26m (8.3%) for A History of Ancient Britain Special.
Bear's Wild Weekend with Jonathan Ross anchored Channel 4's evening with 1.67m (6.1%) at 9pm (+1: 378k/1.7%), prior to which The Hotel mustered 1.78m (6.2%) at 8pm (+1: 316k/1.2%).
World's Strongest Man held 1.47m (5.4%) at 7pm, but Channel 5's evening fell flat afterwards, with a repeat of An Audience with Dame Edna settling for 423k (1.5%).
Overall, BBC One soundly beat ITV1 in primetime with 30.2% to 11% (+1: 1.6%). BBC Two was comfortably in third place with 9.4%, ahead of Channel 4's 5.1% and Channel 5's 3.3%.
BBC Three's film offering of Ratatouille managed a hefty multichannel audience of 1.02m (4.8%), while Sky1's Treasure Island logged 1.01m (3.7%).
BARB ratings data supplied by Attentional