|Lorenzo is now just 35 points behind Casey Stoner in the MotoGP standings [AFP]
Jorge Lorenzo led from start to finish to win the San Marino Grand Prix and end world championship leader Casey Stoner's run of three successive MotoGP wins on Sunday.
Lorenzo's fellow Spaniard Dani Pedrosa took second place while Stoner finished third, his 11th consecutive podium finish.
Australian Stoner had pole position for the eighth time this season but world champion Lorenzo snatched the lead on the first bend and never looked back as he won his third race of the season.
Stoner saw his world championship lead over second-placed Lorenzo cut from 44 to 35 points with five races in the 18-race season still to go.
Andrea Dovizioso is 39 points further back in third place after finishing fifth, having been pipped for fourth spot on the final lap by his great rival and fellow Italian Marco Simoncelli.
Dovizioso had twice overtaken Simoncelli in a fierce battle between the pair.
For the first few laps, Stoner stalked Lorenzo and looked as if he was just waiting for a moment to make his move.
Instead, the Spaniard began to pull clear from the 12th lap and never looked in danger. Stoner, the 2007 world champion, surrendered second position to Honda team mate Pedrosa late in the race.
There was some light drizzle early in the race but the rain held off and the track quickly dried.
"It was just a case of not giving up and keeping working," said Lorenzo.
"The team has done a great job to give me a competitive bike again and...we've been quick all weekend."
"I expected a very hard fight with Casey but fortunately for me he lost some pace in the middle of the race."
Stoner blamed sleepless nights for his performance.
"The bike felt pretty good, we were happy with the way the bike was performing," he said.
"I was sitting behind Jorge because there was some water and I didn't want to be the one hitting the wet patches.
"I was comfortable, everything was working really well but halfway through the race, I just started getting tired.
"My arms were struggling on the brakes, I ran wide a couple of times, started braking earlier and it built from there.
"These last few races have been pretty tiring and a few bad nights' sleep didn't help. It was a tough race today, Jorge rode a fantastic race, he didn't make any mistakes, so he was able to pull away at the front."
Seven-times world champion Valentino Rossi made a tremendous start as he burst from 11th on the grid to fifth place in the opening laps, before eventually finishing seventh.