BOSTON -- Eighty games in, the Boston Red Sox had already proven themselves to be an elite offense.

They reminded everyone of that in their 81st on Sunday.

Boston scored 10 runs and pounded out 16 hits to bounce back from an unsightly 21-2 loss the night before in a 10-5 victory over the Los Angeles Angels at Fenway Park.

"To this point in the schedule, I think this is a very good offensive team," Red Sox manager John Farrell said of a team that hit the halfway point with a major league leading 451 runs.

Pitching, however, hasn't been a strong suit, as the Red Sox had a 4.48 team ERA entering Sunday. But they received a much-needed solid start from journeyman Sean O'Sullivan.

O'Sullivan (2-0), who had been recalled from Triple-A Pawtucket before the game to make the spot start, left to a standing ovation in the sixth after throwing five scoreless innings.

"That was one of the highlights of my career for sure," O'Sullivan said of the Fenway ovation after allowing three runs on four hits and three walks with two strikeouts.

He had made two other starts for the Red Sox this season, including a May 15 no-decision against Houston in which he allowed six runs on five hits over 4 1/3 innings.

Sandy Leon had a career-high three RBIs, Hanley Ramirez and Dustin Pedroia drove in two runs apiece while David Ortiz, Jackie Bradley Jr. and Marco Hernandez added RBIs for Boston (44-37), which won its first series since taking two of three against Seattle on June 17-19.

Yunel Escobar had two RBIs and Kole Calhoun, Mike Trout and Albert Pujols each drove in a run for Los Angeles (33-49), which couldn't build on Saturday's bludgeoning of Boston and lost for the 11th time in 13 games.

Angels starter Matt Shoemaker (3-9) cruised through four innings before unravelling, giving up five runs on nine hits and two walks with three strikeouts.

"OK, up till that point," Shoemaker said. "Even then, we made some good pitches, got out of some stuff.

"Essentially, though, it's almost all for naught after that fifth."

"One pitch here or there and he's got a little different outcome to his outing," Los Angeles manager Mike Sciascia said.

The Red Sox broke the game open with their seven-run fifth, all in the span of six batters.

Ortiz drove a first-pitch changeup from Shoemaker into the center-field triangle, where it bounced out of play for a ground-rule double, and Pedroia scored from second.

It was Ortiz's 1,157th career extra-base hit, tying him with Red Sox legend Carl Yastrzemski for 12th on major leagues' all-time list.

Pujols ranks 11th all time with 1,185 extra-base hits, and Alex Rodriguez led all active players with 1,272 entering Sunday.

One at-bat later, Ramirez poked a slider into right field that rolled to the wall for another double, plating Xander Bogaerts and Ortiz.

Bradley Jr. brought Ramirez home with his single to right and advanced to second on the throw to the plate, then Leon doubled high off the wall in left to score two after Brock Holt walked.

Leon then scampered home on Hernandez's single to left, which was mishandled by Angels left fielder Jefry Marte -- but that was the end of the damage in the frame, mercifully.

Los Angeles answered with three runs in the sixth as Calhoun's RBI double was followed by Trout's run-producing groundout and another RBI double from Pujols.

Escobar drove in a pair with a one-out double in the seventh after a challenge overturned a call that Andrelton Simmons' two-bagger to left was foul, putting runners on second and third.

Leon knocked in another run with an infield single in the Boston seventh before Pedroia plated two with a bases-loaded single to restore a five-run advantage.

NOTES: Boston optioned RHP Pat Light to Triple-A Pawtucket before Sunday's game to make room for starter RHP Sean O'Sullivan. ... The Red Sox agreed to terms with 2016 draft picks RHPs Shaun Anderson (third round) and Matthew Gorst (12th). They were assigned to Class A Lowell. ... Red Sox DH David Ortiz joined the Boston Celtics' recruitment of star free agent Kevin Durant. "Yo (Kevin) sorry I couldn't make the meeting today but (Tom) Brady will tell (you) they don't call Boston the City of Champions for nothing," Ortiz tweeted Saturday. ... Los Angeles RHP Jhoulys Chacin (2-5, 6.11 ERA) was moved to the bullpen. He had allowed fewer than four runs once in his last six starts. ... Angels RHP Nick Tropeano (3-2, 3.25 ERA) was named the starter for Monday's game at Tampa Bay. Boston starts RHP Rick Porcello (9-2, 3.78 ERA) on Monday against Texas.