BOSTON -- Williams Perez rose to the occasion once again Monday night.

The rookie right-hander didn't allow an earned run for the second straight start as the Atlanta Braves beat the Boston Red Sox 4-2 Monday night while handing the Red Sox their seventh straight loss.

"I couldn't have asked for anything more," Braves manager Fredi Gonzalez said.

Perez (3-0) was pitching for the third time in six days after tossing a scoreless inning and recording a save on Saturday in the Braves' 5-3 win over the New York Mets.

"It didn't bother (me) because (I) didn't make too many pitches the other day and (I) didn't make too many pitches today," Perez said through a translator.

On Monday, Perez threw 79 pitches -- 49 for strikes -- and gave up five hits, all singles, while walking two and striking out two over six innings to lower his ERA to 2.29 for Atlanta (31-33), which won at Fenway for the first time since 2012 and ended a six-game losing streak to the Red Sox.

The 24-year-old has yet to lose in his career and is one of four major league pitchers this season with five-plus starts and no defeats.

"I've just been impressed with the young man, just with the way he's carried himself," said Gonzalez. "He knows how to pitch."

Right-hander Jason Grilli let three runners get on base and gave up an unearned run in the ninth, but still managed to record his 17th save of the season.

Boston (27-38) fell 11 games under .500.

Rick Porcello (4-7) dropped his fifth straight decision, allowing four earned runs on six hits and one walk while striking out five in 6 1/3 innings for the Red Sox. The right-hander, who hasn't won since May 16, posted zeros in the first three frames before running into trouble.

"I was sinking it well in the right-handed hitters," said Porcello. "All the pitches were working again. Just the one inning where they put up three runs. That was it."

Pablo Sandoval went 2-for-4 for Boston and collected his 1,000th career hit on a two-out double in the ninth. The third baseman also notched his 200th career double in the seventh.

Xander Bogaerts hit his third home run of the season with one out in the seventh. The shortstop crushed a 2-2 pitch into the center-field bleachers to give the Red Sox their first run.

In the ninth, center fielder Mookie Betts capitalized on a shaky Grilli, sending a 3-2 pitch into left-center to plate a run with runners on the corners and two outs in the ninth.

"We don't really get anything going until Bogie hits the home run, then the single by Mookie in the ninth," Red Sox manager John Farrell said.

Atlanta struck for three runs in the fourth. Right fielder Nick Markakis hit a line-drive single to left field to score the game's first run and later scored on a wild pitch from Porcello with catcher A.J. Pierzynski at the plate.

Pierzynski hit a ball to first that deflected off of first baseman Mike Napoli's glove and rolled into right, bringing third baseman Juan Uribe home to make it 3-0.

Second baseman Jace Peterson had an RBI single to right in the seventh to make it 4-0.

Braves left fielder Jonny Gomes, a World Series hero for the Red Sox in 2013, was cheered in his return to Fenway and finished 0-for-3. Gomes made a diving catch in left to rob second baseman Dustin Pedroia of a leadoff hit in the bottom of the fourth.

"I've been in a couple organizations and I always thought that it was cool when an opposing player comes back, you get the standing ovation," Gomes said. "It's pretty cool that the fans appreciate, and obviously these are pretty knowledgeable fans."

The same cannot be said for Pierzynski, who was booed in his first game back at Fenway since the Red Sox cut ties with him after 72 games in 2014.

"A.J. has fond memories here," Gonzalez said. "I know he didn't fin