England went into the game as genuine underdogs, with commentators and fans alike writing off their chances against a confident Australian team.
A thrilling 12-10 victory over the Wallabies was watched by an average audience of 5.2m and a 49.3% share during the match itself, which kicked-off at 2pm on Saturday.
ITV's entire coverage of the event, including pre and post-match analysis, attracted 3.7m and a 37% share, from 1.10pm-4.30pm.
ITV's viewing figures are set to benefit again on Saturday when England progresses to the semi-finals of the Rugby World Cup in a match against host nation France.
The commercial broadcaster paid £40m for the exclusive UK rights to the 2003 and 2007 Rugby World Cup tournaments and was banking on the 2007 tournament generating a significant return on its heavy investment.
ITV has generated strong advertiser interest in this year's tournament up until now and, according to Media Planning Group, if England were to make the final it would generate an extra £7m in advertising revenues.
Simon Shaps, ITV director of television, said: "[Saturday's] thrilling Rugby World Cup quarter-finals were television sport at its most gripping and have set up a mouth-watering semi-final clash between England and France next Saturday."
In Saturday's other quarter-final, France's surprise defeat of tournament favourites New Zealand drew an average audience of 5.7m and a 25% share, between 8pm-9.30pm.
The entire coverage, which was scheduled in a 7.45pm-10pm slot, was watched by an average of 5.3m and a 24% share.
Amir Khan's successful defence of his Commonwealth lightweight title against Scott Lawton followed the rugby at 10pm.
The live coverage on ITV1 peaked at 4.9m and a 26% share as the 20-year-old from Bolton won with a fourth-round stoppage.