Misano - Reigning world champion Jorge Lorenzo won the San Marino Moto Gp here on Sunday on a Yamaha to narrow the gap on current series leader Casey Stoner.
The 24-year-old Spaniard came home clear of compatriot Dani Pedrosa, riding a Honda, while series leader Casey Stoner of Australia, who started from pole, was third, also on a Honda.
Lorenzo - who celebrated by hurdling the barrier between him and his mechanics, landing in their arms - reduced the gap between him and Stoner to 35 points.
Stoner was gracious in defeat but, worryingly, his reasons for losing suggested that he might be falling victim to a mystery illness he has had before when he complained of feeling weary.
"There is no excuses as everything felt really good including the bike," said 25-year-old Stoner, who was world champion in 2007.
"I didn't want to push too hard in the rain at the start and was content to sit in behind Lorenzo.
"I felt comfortable just behind Lorenzo and then made an attack but when I tried to go for it I felt tired, my arms especially. I was worn out. No excuses I am just worn out after the last three races (including two in America)."
Meanwhile, Lorenzo was ecstatic to be back on the top step of the podium.
"I really needed this victory because the last two races have been a nightmare so to be back with a really good bike is great," said Lorenzo.
For Pedrosa it was another outstanding result since his comeback from a broken right collarbone in the French race in May, an injury which saw him miss three races, ruining his chances of winning the world title.
"It was really tough (the race). A very demanding circuit. The bike was not like what I wanted," said the 25-year-old.
"I couldn't push it but I could at least catch Casey towards the end."
Lorenzo led Stoner by nearly four seconds with nine laps remaining while Pedrosa was in third.
Pedrosa, though, paid no respect to the series leader and, clearly with no team orders, passed his Australian team-mate with five laps remaining while behind them, Marco Simoncelli, Ben Spies and Andrea Dovizioso were involved in a battle for fourth spot.
Stoner kept on losing time to Lorenzo, and was seven seconds adrift with four laps remaining, just conserving his place and thus preventing the Spaniard from gaining any more points on him.
Simoncelli had a thrilling duel with his compatriot Dovizioso, with the latter passing him with just over a lap to go.
However, Simoncelli refused to let it go and reclaimed his fourth spot almost immediately to prevail by 37 hundredths of a second.
Veteran Loris Capirossi failed to get a fairytale result just days after announcing he was retiring at the end of the season as the 38-year-old Italian - who has competed at Grand Prix level in all categories since 1990 - failed to finish.
San Marino motorcycling Grand Prix results on Sunday:
MotoGP
1 Jorge Lorenzo (ESP) Yamaha 44min 11.877sec, 2. Dani Pedrosa (ESP) Honda at 7.299sec, 3. Casey Stoner (AUS) Honda 11.967, 4. Marco Simoncelli (ITA) Honda 17.353, 5. Andrea Dovizioso (ITA) Honda 17.390, 6. Ben Spies (USA) Yamaha 18.092, 7. Valentino Rossi (ITA) Ducati 23.703, 8. Alvaro Bautista (ESP) Suzuki 30.678, 9. Hector Barbera (ESP) Ducati 37.502, 10. Cal Crutchlow (GBR) Yamaha 37.720
11. Hiroshi Aoyama (JPN) Honda 39.548, 12. Karel Abraham (CZE) Ducati 40.506, 13. Colin Edwards (USA) Yamaha 53.349, 14. Randy de Puniet (FRA) Ducati 1min 02.366sec, 15. Toni Elias (ESP/Honda) 1:20.156
Did not finish: Loris Capirossi (ITA) Ducati, Nicky Hayden (USA) Ducati
Moto2
1. Marc Marquez (ESP) Suter 43min 08.197sec, 2. Stefan Bradl (GER) Kalex at 0.619sec, 3. Andrea Iannone (ITA) Suter 0.713, 4. Alex De Angelis (SMR) Motobi 1.634, 5. Scott Redding (GBR) Suter 3.275, 6. Bradley Smith (GBR) Tech3 3.436
125cc
1. Nicolas Terol (ESP) Aprilia 40min 02.164sec, 2. Johann Zarco (FRA) Aprilia at 0.022sec, 3. Efren Vazquez (ESP) Derbi 4.932, 4. Sandro Cortese (GER) Aprilia 9.322, 5. Hector Faubel (ESP) Aprilia 9.964