- Spanish motorcyclist Jorge Lorenzo wins on home soil to extend championship lead
- The 2010 world champion heads home compatriot Dani Pedrosa in Sunday's race
- Last year's winner Casey Stoner loses ground in standings after finishing fourth
- Seven-time world champion Valentino Rossi is back in seventh for Ducati
Jorge Lorenzo extended his MotoGP series lead to 20 points after winning the Catalunya Grand Prix for the second time in his top-level motorcycling career.
The Yamaha rider started Sunday's race from second on the grid, but outshone Honda's polesitter Casey Stoner as the reigning world champion lost more ground in the overall standings after finishing fourth.
It was Lorenzo's third victory in five races this season, and second in a row after winning at Le Mans last month. He was runner-up in his two other MotoGP starts at Montmelo, and also won there with Aprilia in the 250cc class.
He came home five seconds ahead of fellow Spaniard Dani Pedrosa, with Italy's Andrea Dovizioso third on a Monster Yamaha Tech 3.
"I'm really happy with this victory as it was a very tough weekend. We performed a lot better than yesterday as in qualifying it was very hot," said the 2010 world champion, who had to make up ground after Pedrosa took the early lead.
"The grip on the track after the rain this morning was also not so great. I followed Dani and watched him, he slowed his pace and eventually made a mistake so I was able to pass him then give it full throttle."
Pedrosa was disappointed despite finishing on the podium at Montmelo for the eighth time, being 10 points behind teammate Stoner in third overall.
"A second place is always a second, but I really wanted to win today, I cannot feel happy," he said.
"I tried to attack but with 10 laps remaining I couldn't keep the pace. It was hard to control the bike on braking and in the exit of the corners, so I was defensive because I knew my corner speed was not so good. I made a mistake and I had a big wheelie, so Jorge got past me and I couldn't follow him."
Stoner, who plans to retire at the end of this season, was also disappointed -- having won the previous four races held at Spanish circuits.
"We gave it everything at the end but we just didn't have the pace, especially in the beginning with the hard tire," the Australian said.
"With the performance we had during the weekend we expected to be a little stronger throughout the race."
Dovizioso's British teammate Cal Crutchlow was fifth ahead of Spain's Alvaro Bautista and seven-time world champion Valentino Rossi of Ducati.
Germany's Stefan Bradl was eighth on a Honda, with Ducati's Nicky Hayden ninth and fellow American Ben Spies 10th.
Spies dropped from second early in the race, which was a big blow after qualifying in fourth on Saturday.
"I just made one mistake in the race and blew our chance," the 27-year-old said. "We were going good in the beginning but I was getting impatient with Dani.
"He was holding me up but I couldn't make the pass on the straight so I had to go for it on the brakes and unfortunately got out onto the edge of the track. I got up and we got back into it and our pace was pretty good, unfortunately it was too late to get back to the front."