The BBC2 launch of critically acclaimed US drama Heroes last night helped power the channel to what is believed to be its biggest peaktime ratings win over BBC1 since 1994.
BBC2's superhero series, which has already been broadcast on cable and satellite channel Sci Fi earlier this year, launched from 9pm with an impressive 4.3 million viewers and a 19% share.
The second episode ran immediately afterwards at 9.40pm, and that picked up an audience of 4 million viewers, according to unofficial overnights.
There will be more cheer for the BBC too in the fact that Heroes was more popular with young viewers than Big Brother.
Billed as "geek heaven" by TV critics, and one of the few hits of last autumn's new US TV season on NBC, Heroes was in danger of overheating from pre-premiere hype.
But the BBC's gamble on the show, which the director general, Mark Thompson, has described as "wholesome" and reportedly cost the corporation ?500,000 an episode, appears to have paid off.
However, it was given a big helping hand by a special hour-long edition of Top Gear, scheduled before Heroes last night in the BBC2 8pm hour.
Top Gear - Polar Special drew 4.5 million viewers and a 21% audience share. These are good figures for BBC2, although below Top Gear's stellar audiences of up to 8 million for the series broadcast earlier this year after presenter Richard Hammond's recovery from a life threatening high speed crash.
The BBC2 car show froze out National Lottery Jet Set on BBC1, which averaged 1.9 million viewers between 8pm and 8.30pm; and Vet Safari, which drew 1.8 million between 8.30pm and 9pm.
BBC2 beat BBC1 last night in peaktime, between 7pm and 10.30pm, by what is believed to be the biggest margin for 13 years.
Although BBC2 beat its bigger sibling a couple of times last year in peaktime when The Apprentice was on, plus on July 31 2005 when BBC2 had a combination of Coast and Top Gear, those were tiny wins of around less than half a share point.
Last night BBC2 beat BBC1 in peak by 2.4 share points, according to unofficial overnights.
The last time the gap was larger was June 27 1994. That day Wimbledon and a World Cup game between Germany and South Korea meant BBC2 beat BBC1 by 10.7 share points.