WASHINGTON — Back where it all started, right-hander Lucas Giolito shined in an 11-2 runaway win over the Nationals at Nationals Park on Friday.

Pitching for the first time against the team that drafted him, the right-hander was dominant again, winning his fifth decision in a row, tossing a season-high 7 2/3 innings and allowing one run.

“It was good,” manager Alex Cora said. “Good fastball command, the changeup was great. He didn’t want to come out. I appreciate that. He’s a competitor. He feels like the more pitches he throws, the better it is for him.”

Trevor Story crushed a two-run homer, his 13th on the season, finishing 4-for-5 with three runs scored and four RBIs as Boston racked up 16 hits for its fourth win in six games, snapping a five-game road losing streak.

“Felt good. Kind of a tough 11 a.m. start, but just get the minimal routine [in] and just go compete,” Story said. “I think that was the main message. We have a chance to control our destiny here, so we got to set the tone here on the first game, and I think we did that today. Looking forward to the rest of the series.”

Jarren Duran added two hits and three RBIs. Roman Anthony reached base five times on two hits, two walks and a hit by pitch, scoring a run.

Giolito appeared in six games (four starts) for the Nationals in 2016. Friday, he scattered four hits and struck out seven with three walks, 10 days before his 31st birthday. Giolito fired 108 pitches, 75 for strikes, mixing his slider, changeup and four-seam fastball, reaching 96.3 mph.

“It’s been a long road,” Giolito said of his pro debut in D.C. “I pitched very different back then, very long arm action. I think [in] every baseball player’s career, you have your ups and downs. Even the downs, when you come back from those, it’s probably more satisfying than just being good all the time. I just look forward to continuing to work and for us to really get hot and start winning a lot more games.”

The right-hander was a highly touted 17-year-old when the Nationals selected him with the No. 16 overall pick in the first round of the 2012 Draft. He was later traded to the White Sox in 2016, along with Reynaldo López and Dane Dunning, for outfielder Adam Eaton.

“It was good. I like going deep into the game,” Giolito said. “It’s important for us to do that. Alleviate the bullpen a little bit … continuing to make good progress and staying consistent. That’s been my goal pretty much my whole career. Too much lack of consistency. So it’s good to be in that spot. I just want to keep it going.”

Giolito (5-1) has now faced 28 of 30 Major League teams, having not pitched against the White Sox (his former team) and the Dodgers.

Giolito made his debut for the Nationals in their 5-0 shutout of the Mets on June 28, 2016, tossing four scoreless innings and allowing one hit. He did not factor in the decision.

“It’s so long ago,” Giolito said. “Nine, 10 years ago I debuted here. I was definitely excited to come back, because it’s been so long. I checked off another team. I’m not facing any of the same guys. It’s a different team now.”