Few expected anything other than a Lionel Messi-inspired cakewalk at the Lusail Stadium, where the 35-year-old’s early penalty only furthered that feeling.
Argentina went on to have three goals disallowed for offside in a one-sided first half that was followed by a remarkable second period in which the raucous Saudi fans cheered their side to a stunning victory.
Saleh Al Shehri and Salem Al Dawsari scored a quickfire double soon after the restart to put Renard’s men ahead, with goalkeeper Mohammed Al Owais putting in a man-of-the-match display to help see out a famous 2-1 win.
“Congratulations to these fantastic players,” Saudi coach Renard – who spent a short spell as Cambridge boss in 2004 – said.
“I decided to come to this country three and a half years ago and since this time I’ve had the management, amazing president and the ministry of sport were always behind us.
“Even when we visit our prince two, three weeks ago he didn’t put any pressure on us.
We prepared very well and today all the stars in the sky were in the same line for us.
Saudi Arabia coach Herve Renard
“This is the way you have to work in football because when you are putting too much pressure it’s not working all the time.
“We prepared very well and today all the stars in the sky were in the same line for us.
“But don’t forget Argentina are still a fantastic team. They came here without losing lose any game in 36 and they are South American champions.
“They have amazing players, but this is football. Sometimes things completely crazy can happen.”
Renard struck a calm figure amid the excitement in the post-match press conference in the bowels of the Lusail Stadium, which was rocking as Saudi dug deep for a historic triumph.
“Have a good celebration during 20 minutes and that’s it,” the Frenchman said. “There’s still two games – or more – for us.
“When you are coming to the World Cup you need to believe in yourself. Everything can happen in football.
“Sometimes your opponent is not at his best motivation. This is normal.
“It’s also happened to us sometimes when we play a lower team. This is sometimes what the people do not understand.
“Do you imagine Lionel Messi (is highly motivated) against Saudi Arabia? Of course he will say ‘we need to start very well’ but you know motivation is not like they play Brazil. This is normal, this is part of football.
“We made history for Saudi football. It will stay forever. This is the most important thing, but we also need to think about looking forward because we still have very difficult two games.”
Argentina are among the favourites to lift the World Cup at the Lusail Stadium on December 18 but began the finals with a defeat for the first time since Cameroon stunned them in 1990.
Messi – who became just the fifth players to score in four different World Cups – struck a frustrated figure after Tuesday’s shock loss in this Group C clash.
“It is a very hard blow for everyone,” said the Argentina captain, who is an ambassador for Saudi tourism. “We did not expect to start this way. Things happen for a reason.
“We have to prepare for what is coming, we have to win, and it depends on us.
“There are no excuses. We are going to be more united than ever. This group is strong, and we have shown it. It is a situation that we haven’t gone through in a long time. Now we have to show that this is a real group.
“We knew that Saudi Arabia is a team with good players, that they move the ball well and that they push (forward) the (defensive) line a lot.
“We worked on it, but we rushed a bit. We have to go back to the base of who we are. We have to think about what’s next.”