Damon Hill was deprived of victory on the last lap of a thrilling Hungarian Grand Prix at Hungaroring yesterday. In what would have been one of the biggest upsets in Formula One history, the reigning champion led by over 30 seconds with two laps to go and was coasting to victory in his unfancied Arrows Yamaha.

However, disaster followed when a technical fault with his throttle forced him to slow and try to coax the car home. As the hydraulic fluid seeped out of Hill's engine, it became a countdown to the finish with the alerted Jacques Villeneuve eating into his lead. The French-Canadian eventually appeared in Hill's rear-view mirror and surged past on the grass to take the lead on the final lap and steal a precious win.

Villeneuve's victory moves him to within three points of Michael Schumacher in the 1997 World championship title chase. Ralf Schumacher finished fifth for the Benson and Hedges Jordan team, just feet behind his brother who had earlier seen off a challenge from Giancarlo Fisichella.

Eddie Irvine also suffered last lap horrors after being punted out of sixth place by Prost driver Shinji Nakano.

But the day belonged to Hill. Not since Jody Schecter won first time out in the Wolf in 1977 has a more unlikely combination headed for the top place on the rostrum, as the Killiney-based Englishman drove his Arrows at a pace hitherto totally absent.

Aided by the Bridgestone tyres, Hill started from third place on the grid, grabbed second place in the sprint to the first corner and in an audacious move, muscled past Michael Schumacher to take the lead on lap 10.

He then dominated the 77-lap race with the conviction and confidence of a World Champion but where the three seconds a lap the car has gained since Hockenheim a fortnight ago has come from, no one, not even Hill, knows: "It is a combination of things really. The Bridgestones were very good here. My experience here (he won in '93 and '95) allowed me find a good set-up quickly. Yamaha and the team have been working very hard," he said afterwards.

Arrows have entered 299 Grands Prix without a win and Hill has scored only a single point this year. For both team and driver, the problems in the closing stages were simply cruel beyond words. "About five laps from the end the hydraulics started to act up," said Hill, who explained that the throttle position and gear-change are both effected by hydraulic power on electronic instruction.

"On the last lap I was stuck in gear and the throttle was sticking. Before the problem I was 30 seconds ahead of Jacques but I needed to be 40," said Hill, who in a most sporting gesture enthusiastically congratulated his former team-mate Villenueve, on his win.

Michael Schumacher finished fourth and the three points earned keeps him narrowly ahead of Villeneuve in the title chase. In the closing laps Schumacher was being challenged by his brother Ralf in a duel that raised all sorts of issues. But in the end, Ralf showed uncustomary caution: "I was a lot quicker than Michael," explained the tall Jordan driver, "but I felt to have tried any harder to overtake him would have been too much of a risk. I nearly spun twice as it was so I decided to back off and save my fifth position. I knew he would not give up the position easily and it would have been really stupid if we had both lost our places if things had gone wrong," he added.

Had they gone off, Villeneuve would be level with the elder Schumacher in the championship - hardly conducive to brotherly love.

A questionable tyre strategy - going for hard tyres and less pit-stops - was again used by Jordan, following the initiative in Germany. The team's worst qualifying of the year - they started on the seventh row - left them a lot to do but Eddie Jordan felt points finishes were possible if the drivers simply stayed on. "We should have had two cars in the points," said the team boss.

Fisichella was battling Michael Schumacher for fourth when he spun off. Fisichella is somewhat in awe of the big stars of Formula One and the attempted pass on Schumacher simply didn't have the conviction of Hill's effort at the same spot.

"It was a pity," said Jordan, "I suppose it was inexperience. They are young drivers and this is their first time here. Had Giancarlo finished we would be clear of Prost in the championship."

In the event the single point earned by the Bridgestone-shod Prost of Shinji Nakano is the gap between Jordan and the French outfit. Nakano's point came at the expense of Eddie Irvine: "He just punted me straight off on the last lap," said the Ulsterman who was in third early in the race. "My first set of tyres blistered very quickly. They had only half a lap of real scrubbing on them and on a hot day they needed two laps at least."

With just six races left, yesterday's result has blown the title chase wide open and with Jordan now only one point behind Prost and nine behind McLaren, their bid for fourth place in the constructors' championship is within reach.