Italy and Spain may have slipped up in their first outings, but Argentina yesterday became the third of the tournament favourites, after Brazil and the hosts, to kick off their campaign with a win. Like their South American neighbours, though, Daniel Passarella's players will have to raise their game a gear or two over the coming weeks if they are fulfil their ambitions here. While they deserved their win in this game, they hardly showed the sort of ruthlessness that might be expected of wouldbe world champs.

Moving forward, the Argentinians were every bit as convincing as they had been in Dublin a couple of months ago but when, as often happened, they carelessly surrendered possession with a lot of players committed, they could look shaky in retreat, a weakness that Japan more than once looked capable of capitalising on.

In the Japanese midfield, Hidetoshi Nakata was, as expected, the star of the show, and if he continues to play like this, then the move to Europe he's talked so much about in recent months may well come to pass.

He wasn't the only one of Takeshi Okada's men to make a mark, however, with Motothiro Yamaguchi on the left side of the centre pushing the ball around well and the wing backs, Akira Narahashi and Naoki Soma, causing occasional problems on the break.

At the back, on the other hand, the Japanese were clearly out of their depth. Gabriel Batistuta, Claudio Lopez and Ariel Ortega were all man-marked for the bulk of the game but sometimes they must scarcely have noticed.

Ortega, in particular, proved a thorn in the debutants' side, repeatedly beating his own man and drawing cover out from the centre before feeding the ball to his strikers.

Inside him in midfield, Juan Vernon might, on another day, have bagged a couple of goals with long-range efforts, while the willingness of Diego Simeone, Matias Almeyda and Javier Zanetti to get forward at the drop of a hat was giving the Japanese captain and sweeper, Masami Ihara, a nightmarish time as he attempted to co-ordinate his side's defensive strategy.

He and his team-mates held out until the 28th minute when Ortega stepped over Simeone's through ball and, under pressure, Niroshi Nanami diverted the ball straight into Batistuta's path. The rest was more or less a foregone conclusion, the 29-year-old Fiorentina star chesting the loose ball on and then flicking it neatly past the stranded Yoshikatsu Kawaguchi for his 44th international goal in 62 appearances. After that, it seemed, the floodgates would surely open.

They didn't. Ten minutes later Batistuta met Simeone's angled cross with a beautiful glancing header but the ball came off the inside of the post for Kawaguchi, who recovered his position well to deny Lopez. Then, over the early stages of the second period, the Argentinians seemed to lose their way for a spell.

They could hardly be said to have come under much pressure, although when Almeyda and Roberto Sensini continued to retreat in the face of Nanami five minutes after the restart, you got the feeling a more experienced marksman would, at the very least, have severely tested Carlos Roa with the shot.

During a better spell midway through the half Simeone forced a brilliant reaction save from the Japanese goalkeeper and, after Sensini had made his exit from the proceedings, possibly with a broken finger, Batistuta hit the post from close range again.

His charity might have been punished in the frantic last couple of minutes, Soma first narrowly failing to turn Yutaka Akita's cross in at the far post before Eisuke Nakanishi made fools of Simeone and Almeyda before setting up Japan's Brazilian-born striker, Wagner Lopes, for a shot which only Jose Chamot's desperate block kept out.

Passarella, not generally believed to have the same instinctive feel for defence as attack, must have been wondering what precisely it was that his men thought they were playing at.

The final whistle arrived, though, with Argentina's lead still intact and Passarella, while conceding there were some things which needed a little attention, declared himself generally happy with the way things had gone.

"The main thing is that we won," he said. "After that, everything else is for another day. Sometimes the first game is the most difficult to win and so we can only be satisfied with taking the three points and moving one step closer to the second stage of this competition."

One step close to being out of this competition, meanwhile, was Okada, who paid tribute to his players for the aggression and determination they had shown through the best part of the game.

"We always knew they'd be stronger than us," he admitted. "And so it was unfortunate that after we conceded a goal we couldn't score from one of the chances we created."

It was a hard lesson for a side making its first appearance at this stage of the competition; a useful one for a team with ambitions of winning the trophy for the third time in 20 years.