It’s been a very different story for the Washington Nationals, and that’s been abundantly clear through the first two games of their interleague series.

Xander Bogaerts hit a three-run homer during a six-run fifth inning, J.D. Martinez and Eduardo Nunez also went deep, and Boston beat Washington 11-4 in sweltering conditions Tuesday.

“A lot of guys stepped up,” Bogaerts said. “The weather’s not the best. It’s hot. It’s better than cold. A lot of guys swung at good pitches and had good at-bats.”

Martinez drove in four and leads the majors with 26 homers and 71 RBIs. Boston has won 17 of its last 19 interleague games, including 11 of its last 12.

Washington has lost four straight and 16 of 21 to fall to 42-42, its first time at .500 since it was 17-17.

“It’s hard to play from behind,” Washington manager Dave Martinez said. “Our starting pitching right now is not giving the offense a chance. When we do try and make a run and come back, we got to have shutout innings. It’s not happening.”

Red Sox starter Brian Johnson allowed two runs in 4 2/3 innings. Brandon Workman (1-0) pitched a perfect seventh.

Boston scored first, opening the second with consecutive singles before Nunez homered into the left field bullpen off starter Tanner Roark (3-10). Mark Reynolds and Roark had RBI singles in the fourth to pull the Nationals within 3-2.

The Red Sox responded in the fifth, collecting five consecutive singles before Bogaerts ripped Roark’s fastball to center to make it 9-2.

“We did a good job today against Roark,” Nunez said. “I think he made a lot of mistakes up with the sinker and we took advantage.”

Brian Goodwin and Pedro Severino hit solo homers for Washington.

Roark allowed a career-high nine runs in seven innings and is 1-8 with a 5.19 ERA in 12 appearances (11 starts) since May 5.

“Other than two pitches I feel like they just base hit me to death, so what are you going to do?” Roark said.

TRAINER’S ROOM

Red Sox: 1B Mitch Moreland left in the third inning with back spasms and is day to day. “I wasn’t planning on playing him tomorrow, so definitely he won’t play tomorrow now,” manager Alex Cora said. … LHP Drew Pomeranz (biceps tendinitis) allowed five runs in 2 2/3 innings Monday for Triple-A Pawtucket in his first rehab appearance since Boston placed him on the disabled list June 5. … 2B Dustin Pedroia (left knee inflammation) is likely to remain in New York all week for further testing.

Nationals: RHP Stephen Strasburg (shoulder inflammation) threw about 60 pitches Tuesday. Martinez said Strasburg’s next step could be a simulated game sometime this weekend. … Martinez said 1B Ryan Zimmerman (right oblique strain) could begin a rehab assignment this weekend. Zimmerman has not played since May 9.

ROSTER MOVE COMING

Cora said Boston will activate RHP Tyler Thornburg (shoulder surgery) on Wednesday. Thornburg was acquired from Milwaukee in December 2016 but has not pitched in the majors since. The Red Sox intend to send RHP William Cuevas to the minors. Cuevas allowed a run in two innings Tuesday in his first appearance with Boston this season.

NATS SIGN TOP PICK

Washington signed first-round pick Mason Denaburg on Tuesday. The right-hander was selected No. 27 overall out of Merritt Island High School in Florida in last month’s draft.

UP NEXT

Red Sox: LHP Eduardo Rodriguez (9-3, 4.11 ERA) faces Washington for the first time as the three-game interleague series concludes.

Nationals: RHP Erick Fedde (1-3, 6.00) is coming off his first career victory and gets the nod for Washington’s annual Independence Day morning start.