Jon Lester pitched marvelously in a game overshadowed by a benches-clearing fracas, winning his third straight start and helping Boston defeat the Orioles 4-0 Friday night in Baltimore.

Both teams converged around the mound and plate in the fourth inning after Orioles starter Daniel Cabrera threw a fastball behind the ear of Dustin Pedroia. The pitch came immediately after a balk produced a run to put the Red Sox up 3-0.

"The ball slipped out of my hand," Cabrera said.

As plate umpire Mike DiMuro issued a warning to both teams, Boston manager Terry Francona led the Red Sox from the dugout. After being restrained by his teammates, Cabrera waved his arms at the Red Sox, challenging them.

"They say bad (things). That's something I don't like," Cabrera said.

"I don't think we escalated anything," Francona said. "We're in the middle of a pennant race here. We've got more important things to worry about. You can ask them. It wasn't the focal point of our night; the focal point was the win."

In other AL games, it was New York 3, Kansas City 2; Detroit 6, Seattle 1; Los Angeles 3, Cleveland 2 in 10 innings; Chicago 11, Minnesota 10 in 13 innings; Toronto 7, Tampa Bay 2 and Texas 5, Oakland 3.

Lester (4-0) was outstanding in his eighth start since returning to the majors after a bout with lymphoma. The Boston left-hander struck out four, walked two and allowed one runner past second base.

"As he gets removed from what he went through, and he's able to take the mound and take his five days, his stuff is coming back and his knowledge is getting better," Francona said. "That was good stuff tonight."

Lester said, "It ranks up there. It felt pretty good. Command-wise, it was a lot better this time. I just attacked hitters."

Not in the sense that Cabrera did, of course.

His uncontrolled rage caused tempers to escalate. The Orioles charged from their dugout while relievers from both teams ran in from the bullpen. No punches were thrown, but Cabrera (9-15) and Boston's Kevin Cash - who wasn't in the game - were ejected before order was restored.

"I think he lost his cool," Baltimore manager Dave Trembley said. "I can tell you very honestly it's going to be addressed. I'm just glad Pedroia didn't get hurt."

Boston's Mike Lowell said: "Guys throw as hard as he does, you've got to be careful. If he hits (Pedroia) in the head, he could split him in two. It's not our fault he balked the run in."

Cabrera allowed three runs, six hits and two walks in 3 2-3 innings, his shortest start in 54 games. The right-hander's ejection was argued heatedly by Trembley, to no avail.

Boston took a 2-0 lead in the second inning. Kevin Youkilis drew a leadoff walk and J.D. Drew hit a ground-rule double before Jason Varitek singled in a run and Coco Crisp hit a sacrifice fly.

Crisp singled and worked his way to third with two outs in the fourth before Cabrera was called for a balk.