"The forwards tried to play hard in the second half tonight, but it was not enough," he said.
The Argentinians also know their opponents well; more than half of their team play club rugby in the French championship.
Felipe Contepomi was the lynch-pin for the Pumas, mixing his plays of kicking in behind or holding possession no wider than his inside-centre position to allow his forwards to re-cycle the ball.
The Puma's took control early on with three penalty kicks from Contepomi, and extended their lead in the 27th minute when winger Horacio Agulla intercepted the ball from French flanker Remy Martin.
Two passes and a 30 metre diagonal run later, full back Ignacio Corleto scored the only try of the game, Contepomi's conversion came back off the upright, but Argentina went in at half time 17-9 up.
Some commentators said that having dominated both possession and territory, they should have been further ahead.
The French came back at Argentina after the re-start, but the Puma's defence was inspirational as their forwards thwarted any attempt by the Blues to turn a rolling 20-metre maul into an attempt to burrow over the line.
|Argentina were the stronger team |
and delighted their fans [AFP]
Even when winger Aurelien Rougerie broke away and made a 40 metre run from a Pumas kick, Argentina's defence broke up the attack on the 22 metre line.
Contepomi ended the game with a tally of 12 points, as did France's David Skrela, but he and reserve fly half Frederic Mishelak both missed easy penalties in the second half which could have given France the game.
It was the third time in a row that Argentina faced the host nation in the opening match of a World Cup tournament, but it was the first time they had been victorious.
They lost to Wales in Cardiff in 1999, and to Australia in Sydney four years later.
'We were not good'
It was only the second time in the history of the Rugby World Cup that the home nation had lost, after England were beaten by New Zealand in 1991, and no side has lost a game in the pool stages and gone on to win the competition.
"Argentina should be proud," said their captain, Agustin Pichot.
"We're not the best tactical players or the best technically, but our best resources are the passion and pride when we put on the jersey," he said.
Bernard Laporte, the French coach was well aware of the importance of the match:
"When you begin a World Cup and it is imperative to win the match and you lose ... the sky has fallen in on your head."
"We were not good and it is imperative to raise our game," Laporte said.
France will now face Namibia in their next match in Toulouse on September 16th, but will have to beat a strong Ireland side five days later to stand any chance of progressing from Pool D.
"We have a week to work pretty hard," said Ibanez. "The expectation level of this first game was enormous and we were not really tough enough mentally to deal with that."
Argentina will play Georgia in Lyon on September 11th and will be now be hoping to better their previous World Cup best performance when they reached the quarter-finals in Dublin in 1999, only to lose - to France.