Italian Marco Melandri, riding a Honda, clinched his second victory of the season at the French Grand Prix on Monday.
The 250cc category 2002 champion benefited from Valentino Rossi's woes after the Italian Yamaha rider, who led most of the race, was forced to retire with a broken engine eight laps from the finish.
Italian Loris Capirossi, riding a Ducati, overtook Spanish debutant Dani Pedrosa on a Honda on the last lap to grab second.
Melandri and Capirossi, both on 79 points from five races, put pressure on American leader Nicky Hayden. The Honda rider, who was fifth, had his lead over the two Italians reduced to four points.
Pedrosa, who has won his first GP last weekend in China, is fourth in the standings with 73 points.
Rossi, who has finished only two races since the beginning of the season, dropped to eighth overall on 40 points.
"I started not so good because my tyres were very hard," said Melandri.
"With the track progressively heating, I was much better. But I've been lucky Valentino had to retire because otherwise the win would have been out of reach," he added.
Melandri and Capirossi will have the chance to take the overall lead when they start their home Grand Prix in two weeks.
Capirossi said: "This second place is a very good result for us as the circuit does not suit us.
"I've tried to follow Marco and in the last two laps, I had the feeling I could overtake Dani. It's been a very good weekend for us."
"I knew it would be difficult at the end of the race because of the tyres but it was my choice," added Pedrosa, who had a soft rear tyre.
Five-times champion Rossi, a winner at the French GP last season, overtook early leader John Hopkins on the fifth lap.
"Il Dottore", who was using a new chassis after retiring in China, was starting his seventh consecutive race off the front row. But a mechanical problem forced him to retire for the second successive race.
There was also disappointment in the Kawasaki team with local favourite Randy De Puniet retiring after a crash on the first curve.
Japanese team mate Shinya Nakano, who had qualified second, was given a ride-through penalty for a jump start and finished 12th.
Earlier on Sunday, Japanese Yuki Takahashi, riding a Honda, powered to the first victory of his career in the 250cc race. The 21-year-old overtook overall standings leader Andrea Dovizioso, who has yet to win a race this season, on the last curve.
Dovizioso has 92 points from five races and leads Spaniard Hector Barbera, who finished a disappointing seventh, by 14 points.
In the 125cc race, Switzerland's Thomas Luthi won his first race of the season, capitalising on Alvaro Bautista's mechanical problems on the last lap.
Rossi's curse strikes again