The final auditions show of Britain's Got Talent was by far the most watched programme of the night, with an average of 11.62m (51.1%) between 8.20pm and 9.50pm.
In the hour before Talent, the penultimate episode of Primeval managed a respectable 4.49m (24.8%). The sci-fi drama beat the final episode of John Barrowman's Tonight's The Night, which took 3.99m (22%) for BBC One between 7.20pm and 8.15pm.
The National Lottery - 1 vs 100 had 3.26m (15.1%), then the draw itself delivered 3.97m (17.6%). The latest episode of Casualty put in 4m (17.3%) between 9.05pm and 9.55pm.
Earlier, Robin Hood drew an unspectacular 3.11m (19.3%) between 6.35pm and 7.20pm.
The final instalment of BBC Two's RHS Chelsea Flower Show had 1.88m (9.2%) from 7.50pm, then documentary The Birth Of British Music - this week focusing on Austrian composer Joseph Haydn - interested 810k (3.5%).
Channel 4's Born Survivor: Bear Grylls appealed to just 560k (2.6%) in the 8pm hour, after which a rerun of Robert Carlyle drama Hitler: The Rise Of Evil took 1.09m (5.3%).
On Five, an NCIS double bill attracted 773k (3.6%) and 893k (3.8%) from 8.05pm, then a new CSI: NY grew the audience to 2.01m (11.3%). Law & Order closed off prime with 1.09m (9.7%).
ITV1 averaged a massive 33.7% share in primetime overall, around twice BBC One's 17%. BBC Two was third with 7.9%, followed by Five with 6.7% and Channel 4 with 3.8% (+1: 0.5%).
Spinoff show Britain's Got More Talent was the most watched multichannel programme of the day, with 1.26m (7.5%) for ITV2 from 9.50pm. ITV2+1's repeat added 106k (1%).
Ratings data supplied by Attentional