The game, which France were expected to win but ended up losing 12-17 to a spirited performance from Argentina, earned ITV1 an 18% peak share.
Showing at 7.30pm-9.45pm, the game achieved a good audience compared to previous Rugby World Cup openers.
Four years ago, coverage of Australia against Argentina drew a peak audience of 1.6m in the early hours, while Wales versus Argentina attracted a peak audience of 3.5m in 1999.
On Saturday, England got their World Cup campaign off to a winning start with a 28-10 victory over the USA. The match pulled in a small but respectable audience, considering it was scheduled against BBC1's live coverage of the England football team's crucial Euro 2008 qualifier against Israel.
ITV1's coverage earned an average audience of 2.2m and a 15% share, between 4.45pm-7.05pm.
On BBC One at 4.30pm-7.05pm the England football team's comfortable 3-0 win over Israel peaked at 8.6m and a 49% share, with an average audience of 6.1m and a 41% share.
Earlier in the day, ITV1's coverage of Australia's first game, in which the Wallabies trounced Japan 91-3, pulled in 1.4m viewers and a 16% share at 2.30pm-4.45pm.
ITV paid £40m for the exclusive UK rights to the 2003 and 2007 Rugby World Cup tournaments and is banking on the 2007 tournament generating a significant return on its heavy investment.
The commercial broadcaster has generated strong advertiser interest in this year's tournament and it is forecast that if England were to make the final, it would generate an extra £7m in advertising revenues, according to Media Planning Group.