BALTIMORE — Rick Porcello and the Boston Red Sox appear poised to extend their late-season charge deep into October.

Porcello pitched a four-hitter for his major league-high 21st victory, David Ortiz and Mookie Betts hit two-run homers and Boston beat the Baltimore Orioles 5-2 on Monday night to pad its lead in the AL East.

Coming off a four-game sweep of the Yankees, the Red Sox extended their surge in the opener of an important four-game series for both clubs. Boston has won 10 of 13 and stands atop the division by a season-high four games.

"It's never over until it's over, but we're definitely going to try to increase the gap between us and them," Porcello said.

Adam Jones homered and Mark Trumbo picked up his 102nd RBI for the second-place Orioles, who started the day with a one-game lead over Toronto for the top AL wild card.

"We've got three more here against (the Red Sox)," Baltimore's Manny Machado said. "We'll just put it on a track where we need to be."

Boston's goal over the next three days will be to put away the Orioles for good.

"We're going to try," Ortiz said.

Porcello (21-4) struck out seven and walked none in his third complete game of the year. Five days earlier against Baltimore, the right-hander gave up one run in eight innings but took the loss.

In this one, he threw only 89 pitches — 65 in the strike zone.

"When it's his day on the mound, he sets the tone for us," manager John Farrell said. "Did once again."

Porcello has allowed three runs or fewer in 11 straight starts and is sure to receive strong consideration for the AL Cy Young Award after going 9-15 last year.

"All of us are honoured to be mentioned for those awards," he said. "But I've been saying it all year, our focus is winning and what we want to accomplish as a team."

Playing his final regular-season series in Baltimore, the 40-year-old Ortiz connected against rookie Dylan Bundy (9-6) with a man on in the fifth for a 5-1 lead. It was his 35th home run of the season and the 53rd of his career against the Orioles.

When he finally walks away from the game, Ortiz will certainly miss taking his cuts at Camden Yards.

"Yeah, man, it's just super nice. I like it," he said, "especially when it's warm like it is."

Betts put Boston up 2-0 with his 31st homer in the third. It was his eighth home run in seven games at Camden Yards — most in a season by a Red Sox in a visiting ballpark since Jimmie Foxx hit eight in St. Louis in 1939.

Porcello retired the first 11 batters before hitting Machado with a pitch in the fourth. Trumbo followed with an RBI double.

The Red Sox responded with a three-run fifth. Dustin Pedroia snapped an 0-for-12 skid with a run-scoring single before Ortiz launched a 1-1 pitch over the 25-foot scoreboard in right field.

Jones homered in the eighth, his 28th.

TRAINER'S ROOM

Red Sox: RHP Steven Wright (shoulder) has started a throwing program at the team's spring training facility in Fort Myers, Florida, but Farrell did not give an estimated date for his return. Wright (13-6, 3.33 ERA) last pitched on Aug. 31. . Farrell said OF Andrew Benintendi has been cleared to play in back-to-back games. He returned from a left knee sprain last Tuesday.

Orioles: OF Steve Pearce will have surgery to repair flexor tendons in his right forearm in New York on Wednesday and is expected to be out 4-6 months. Baltimore placed Pearce on the 60-day DL on Sunday. . LHP Wade Miley threw Monday and is feeling much better after leaving Sunday's start with a strained muscle in his back, manager Buck Showalter said.

UP NEXT

Red Sox: Former Oriole Eduardo Rodriguez (2-7, 4.98) makes his fourth start this season against Baltimore on Tuesday night. He's 1-1.

Orioles: Kevin Gausman (8-10, 3.43) seeks his sixth straight victory. The right-hander blanked Boston over eight innings to beat Porcello last Thursday night.