An average TV audience of 9.4 million viewers tuned into the UK's first prime ministerial debate on ITV1 on Thursday, according to early overnight figures.
At its peak, the showdown between Prime Minister Gordon Brown, Conservative leader David Cameron and Lib Dem leader Nick Clegg was seen by 9.9 million.
Its lowest audience was 8.8m at the start of the debate at 2030 BST, and by the end was seen by 9.3m people.
Nearly 45,000 users watched the live stream video online.
POLITICS ON TV
Election Night - BBC One: 2.38m (5 May 2005)
Tony Blair steps down (Ten O'Clock News) - BBC One: 4.79m (27 June 2007 )
President Obama: A Newsnight Special - BBC Two: 1.45m (5 November 2008 )
Nick Griffin on Question Time - BBC Two: 8.35m (23 October 2009)
Piers Morgan's Life Stories: Gordon Brown - ITV1: 4.26m (14 February 2010)
Ask The Chancellors - Channel 4: 1.7m* (29 March 2010)
*Provisional overnight figure
Two further debates will be broadcast by Sky and the BBC over the next two weeks in the run-up to the general election on 6 May.
The historic debate was the most watched show of the day and had more viewers than the other four terrestrial channels combined at the time of its broadcast.
BBC One's satirical panel show Have I Got News For You was shown at 2100 BST, pulling in 4.3 million viewers, a slight drop from its usual audience of five million.
The debate's average audience share was 37%, with a high of 38.6% at 2100 BST, and a low of 36% at 2030.
Mr Clegg, Mr Cameron and Gordon Brown clashed over issues including tax, immigration and expenses during the debate.
Foreign affairs will be the focus of the next debate, to be shown on Sky News on 22 April.
That will be followed by a final debate on the economy, to be aired on BBC One on 29 April.