The South Africans rarely threatened a well-organised French side in the 3-0 defeat in Marseilles and Fish insists they must now go on the attack against Denmark in Toulouse on Thursday.
"There were not too many positives to be taken from the match. We'll have to go back to basics if we want to beat Denmark and Saudi Arabia," said the Bolton Wanderers player.
"It is essential that we rediscover the type of football which got us here in the first place. We need to be far more attacking from now on - not just because we obviously have to score goals, but also because if we're going forward, it takes the pressure off the defence.
"They deserved to beat us, but the three goals we conceded were very soft. It was a very frustrating night for us."
Fish's candid assessment of South Africa's lacklustre display was not echoed by his coach, the Frenchman Philippe Troussier, who insisted that it had been his team's intention to attack Aime Jacquet's powerful French side. The 43-year-old, who took Burkina Faso to the semi-finals of the African Nations' Cup earlier this year, insists his team can still reach the second round.
"The World Cup is not finished for us just because we've lost to France, who I always thought were favourites to beat us," Troussier said. "From now it is simple - we must take six points from Denmark and Saudi Arabia, and I hope that France will help us by beating both of them as well."
Their task has not been helped by the loss of their most dangerous striker, Benedict McCarthy, for the Denmark match with damaged ankle ligaments.
In addition, McCarthy's striking partner, the former Leeds United player Phil Masinga, is doubtful for the game in Toulouse after suffering a badly bruised shin last night.
The Ajax striker McCarthy was carried off the pitch with his left ankle in a brace during the second half on Friday after collapsing near the centre circle.
"To all intents and purposes he's out of the Denmark match," confirmed the team doctor, Victor Ramathesele. "But he has a decent chance of making the Saudi Arabia game [on 24 June in Bordeaux]. With a bit of rest and some treatment he may be OK."
Meanwhile, Masinga, who now plays for Bari, is to undergo an X-ray in Vichy, as Ramathesele admitted he was concerned about the seriousness of the injury. "It looks bad. He's having trouble putting his weight on it, so we're going to check it out," the team doctor added.
South Africa's other injury concern, the 20-year-old Delron Buckley, is expected to recover in time for the Denmark match. He strained his ankle ligaments last week in training.
The Jamaican midfielder Fitzroy Simpson has revealed his ambition to move to a European club to further his career. He believes his days are probably numbered at Portsmouth as he yearns to play abroad once France 98 is over.
Simpson, who should be in the Jamaican team against Croatia in Lens today, said: "Portsmouth know how I feel, and if they can get back the money they paid for me, then it could be the best for everyone.
"I'm 28 and this is the biggest thing that is ever going to happen to me. I'm finding myself playing against world stars and I know I can hold my own. It's fantastic."