BOSTON -- The rain is the only thing that halted another strong daytime start for Jon Lester.

Jason Varitek homered and drove in three runs to back Lester's solid start, leading the Boston Red Sox to a 9-3 win over the Oakland Athletics on Saturday in the opener of a rain-soaked split doubleheader.

Two delays totaling 3 hours slowed a game moved up to noon to make room for the nightcap that was rescheduled from Sunday to avoid Hurricane Irene's effects. Fans with tickets for the 5:05 p.m. start were allowed through the turnstiles during the 2-hour, 15-minute delay in the eighth inning of Game 1. The game ended at 6:08 p.m.

It also ended Lester's start after six innings. He allowed only two runs, one of them earned, walked two and fanned four, improving to 7-0 with a 1.54 ERA in nine afternoon starts.

Lester (14-6) held down an Oakland lineup that had averaged nine runs in its previous four games.

"His cutter's been tremendous," Red Sox manager Terry Francona said. "Once it rained, he was through."

Lester started under bright skies but heavy rain fell on and off during the middle innings before play was halted the first time as he was ready to take the mound in the seventh. He didn't come back when the game resumed after the first delay of 45 minutes.

"The conditions were really bad. The mound wasn't bad, but anytime you took the ball out of your glove it was wet," he said. "I had no grip. I was trying to tell the umpires that. Maybe the second time it went to the backstop made them realize it wasn't safe."

David Ortiz added a pair of doubles and drove in two runs and Mike Aviles collected three singles for Boston, which won for the seventh time in 10 games to improve its AL East lead to 1½ games over second-place New York.

Brandon Allen hit a solo homer for Athletics. Oakland lost for just the fourth time in 11 games one day after scoring a season-high 15 runs to win the series opener.

Michael Bowden pitched the final two innings.

The second delay came after Varitek bounced weakly to the mound, ending the seventh.

Crew chief Tim McClelland told a pool reporter between games that the first game had to end before the second could be started. No way to call it early and then finish the doubleheader.

"Yes. That's what Joe (Torre) told me," McClelland said.

Torre is the executive vice president of baseball operations.

"Actually there were no options. We were just waiting to get started again," Oakland manager Bob Melvin said. "Both teams have to deal with it. It's not ideal but both teams have to deal with it. So you just play."

Francona said the umpires consulted with MLB regarding the decision to finish the first game before starting the second.

"To play the second game, we've got to play the first one," he said. "I know MLB ruled on it. We've done it the other way a couple of years ago against Minnesota."

In April 2009, Boston led 10-1 against the Twins when the game was halted by rain after seven innings so the teams could get ready for the second game of a split doubleheader.

"That was an aberration," McClelland said. "I talked to Joe. According to the rules, that can't happen or shouldn't happen. They didn't want that. They wanted this game to finish."

The Red Sox scored three runs in each of the second and third innings against Guillermo Moscoso (6-8) to open a 7-2 lead. After Moscoso retired the first two batters in the second, Josh Reddick walked before Varitek homered into Boston's bullpen. Jacoby Ellsbury added an RBI double.

Moscoso gave up eight runs -- seven earned -- nine hits and walked a pair without striking out anyone. It was just the second time in his past six starts he's allowed more than two runs.

Boston moved ahead 1-0 in the first on Dustin Pedroia's RBI single, but Allen homered into second row of seats above the Green Monster to tie it in the second.

Game notes

Adrian Gonzalez's third-inning double gave him a career-high 183 hits. ... Francona said that RHP Clay Buchholz, a key part of the rotation who has been on the DL since June 17 with a strained lower back, will be re-examined in "the next couple of days. But even if the examination is good, he's not allowed to throw until (Sept. 1)." ... Red Sox LF Carl Crawford was back in the lineup after being rested Friday. ... Oakland stole its first three bases (two by Jemile Weeks, one by Cliff Pennington) without even a throw by catcher Varitek. ... The A's recalled Graham Godfrey (1-1) from Triple-A Sacramento in between games to start the nightcap. Boston planned on lefty Erik Bedard (4-9), who is 0-2 since being acquired from Seattle on July 31. ... Cleaning crews were working in the stands during the second delay, trying to get the seats ready for the second game.