ESPN

BOSTON -- Barely a month ago, the New York Yankees were just six games over .500. Now they head into the All-Star break with the best record in baseball and the biggest lead in any division.

To manager Joe Girardi, that's quite an accomplishment.

"I'm proud of these guys because not only have we had injuries, we've had situations where things haven't gone our way," he said after New York's 7-3 win over the Boston Red Sox on Sunday night.

"We struggled with some pitching early on and we struggled with runners in scoring position but the one thing that this group has found a way to do is to win games," he said.

The Yankees have done that in five of their last six games and are 21-8 since going 31-25 through June 7. They've succeeded despite injuries to pitchers CC Sabathia, Andy Pettitte and Mariano Rivera and outfielder Brett Gardner.

"In the beginning of the season we struggled," said Andruw Jones, who hit his fourth homer in three games, a two-run shot in the seventh inning. "Everybody (was) kind of saying we're old, we're not getting the job done. ... We kept battling and kept playing till we got in a groove."

Ivan Nova (10-3) is back in his groove after striking out 10 in six innings while allowing two runs and six hits. He won for the first time in four starts after winning his previous five outings.

The Yankees took three of four at Fenway Park and boosted their record to 52-33 and their AL East lead to seven games over Baltimore.

The Red Sox (43-43) also have been beset by injuries with Carl Crawford sidelined all season so far, Jacoby Ellsbury missing most of the season and Dustin Pedroia and pitchers Clay Buchholz and Andrew Bailey on the disabled list. They dropped their sixth game in the last seven and fell into a last-place tie in the division with the Toronto Blue Jays, 9 1-2 games off the pace.

Only three AL teams -- Minnesota, Kansas City and Seattle -- are below .500 at the break.

Jon Lester (5-6), who won at least 15 games in each of the last four seasons, left with one out in the fifth after giving up five runs and nine hits. Until Sunday, the lefty had rebounded from early-season troubles and posted a 3.86 ERA in 13 starts.

"I just have to go and relax and not think about my first half," Lester said.

The Yankees scored in the first inning in all four games in the series, taking a 2-0 lead in the finale.

"It's tough to be behind, that's for sure," Boston manager Bobby Valentine said.

The first three batters all hit safely on Sunday -- singles by Derek Jeter and Curtis Granderson and an RBI double by Mark Teixeira. Granderson scored when Nick Swisher grounded into a forceout.

The Red Sox got an unearned run in the bottom of the inning when Jeter dropped a routine popup by Cody Ross with two outs. The shortstop's misplay scored Pedro Ciriaco, who had singled and stolen second.

New York made it 3-1 in the second on a double by Jayson Nix, a passed ball by Jarrod Saltalamacchia and a sacrifice fly by Chris Stewart. Boston came back again with a run in the third on Ciriaco's single and David Ortiz's double.

The Yankees drove Lester from the game in the fifth, scoring twice for a 5-2 lead. Teixeira started the rally with a single and scored on a triple by Alex Rodriguez. Jones then singled in Rodriguez.

Nova would have gotten out of a first-inning jam had Jeter held on to the soft popup near second base. The righty even pumped his fist and started walking off the mound but stopped as the ball bounced out of Jeter's glove.

Then Nova struck out the side in the second before escaping trouble in the third when the Red Sox scored a run and loaded the bases with one out. But Saltalamacchia struck out for the fifth time in seven at-bats and Ryan Sweeney grounded out.

Nova fanned three of his last four batters and at least one in each of his six innings.

"I'm getting aggressive, trying to get ahead on the count early and then trying to put them away," he said.

Jones' homer was his 11th of the season and the Yankees' 134th, most in the majors. They're on a pace for a club-record 255. The 1997 Seattle Mariners hold the major league record with 264.

Game notes

Girardi said Jeter had a problem with his shoulder but won't need tests and plans to go to the All-Star Game. .. Robinson Cano extended his hitting streak to 15 games with a double in the ninth, tying Jeter for the longest on the Yankees this year. ... Ortiz's double was his 373rd with the Red Sox, tying Jim Rice for sixth in club history. ... Nova had lost his last road start, ending a streak of 16 starts without a loss away from home. ... Jeter scored his 1,816th run in the first, tying Boston's Carl Yastrzemski for 16th on the all-time list. ... Red Sox 1B Adrian Gonzalez left the game in the third because of illness. He struck out in his only at-bat, ending his career-best hitting streak at 18 games. ... The Red Sox will honor Jason Varitek before their night game July 21 against the Toronto Blue Jays. The catcher retired in February after 15 seasons with the team. ... Ceremonial first pitches were thrown by Ted Williams' daughter Claudia (to Rice) and Babe Ruth's granddaughter Linda Ruth Tosetti (to Ortiz).