David Coulthard put his spat with Michael Schumacher in the previous race firmly behind him yesterday with a well-judged, tactical victory over the Ferrari team in the San Marino Grand Prix.

The 27-year-old Scot beat Schumacher to the chequered flag by only 4.5sec to deprive a fanatical 100,000-plus crowd of its first home victory since 1983.

With four of the season's 16 races completed, only six points now separate the leader Mika Hakkinen, who failed to finish yesterday, from Coulthard and Schumacher in second and third places.

Coulthard seemed to be taking it too easy, slackening off in the closing stages to conserve his McLaren-Mercedes even as Schumacher was closing on him.

In reality Coulthard's car was suffering from an overheated gearbox, a problem which had indirectly forced his team-mate Hakkinen to retire with a broken transmission when in second place and after only 17 of the race's 62 laps.

McLaren's managing director Ron Dennis periodically left his place on the pit wall to check the electronic telemetry system which was monitoring the problem, advising Coulthard to ease up and change gear as carefully as possible during the second half of the race.

"I wanted it run at a pace that wasn't too hard on the brakes or the engine, so I was just trying to maintain the gap to Michael," said Coulthard, unaware of the depth of the problem.

"I was perfectly comfortable to let that gap be reduced because I knew that I could have gone a little faster if necessary. I knew Mika had stopped but I didn't ask why because I didn't want to be worrying about it for the rest of the race."

During Saturday's hour-long qualifying session Coulthard worked hard to secure the seventh pole position of his career, Hakkinen qualifying alongside him to clinch the third all-McLaren front row this season.

Yet neither McLaren driver underestimated the challenge of Schumacher's Ferrari F300. Straining every sinew to make the best possible use of a more powerful V10 engine and a new aerodynamic package, the German driver qualified third, but Hakkinen blocked him out on the first corner and held him back in third place as the two McLarens led the field.

After Hakkinen's retirement, Coulthard maintained his lead over Schumacher through his two scheduled refuelling stops, the Ferrari fleetingly closing to within two seconds before making its own second visit to the pits.

Third place fell to Eddie Irvine although the Ulsterman was under constant pressure from Jacques Villeneuve's Williams FW20 and the reigning world champion finished only four seconds behind Schumacher's team-mate.

"At the start, Jacques beat me off the line and he was quite quick at first, but then I was able to catch him easily," said Irvine. "Later I thought he might catch me but I knew he would not get past. My big problem again was my back, which goes into spasm after about five laps. It was uncomfortable and distracting."

Villeneuve lost crucial time during his first refuelling stop when the flap concealing the refuelling nozzle did not open automatically as intended, something experienced by many motorists in less frenzied circumstances.

"That probably cost Jacques a place on the podium," said Patrick Head, the Williams technical director. "He also lost more time at his second stop, when we had to cut a pipe to the refuelling nozzle. Some you win, some you lose."

At least Williams had the satisfaction of bringing both their cars home in the points, with Heinz-Harald Frentzen following Villeneuve across the line to claim fifth place ahead of Jean Alesi's Sauber-Ferrari.

Damon Hill had raised hopes in the Jordan-Honda camp by qualifying the revised longer-wheelbase car in seventh place but he ran into Alexander Wurz's slow-starting Benetton as the pack accelerated away from the start and had to come in for repairs at the end of the first lap.

Thereafter Hill raced doggedly in the midfield bunch but finally retired with engine trouble when in seventh place only four laps from the end.

Although the Jordan was much more competitive, Hill had hoped that the world championship's return to European tracks would improve his fortunes. Like Johnny Herbert, who again failed to finish after a puncture in his Sauber, he was to be sadly disappointed.