Stephen Strasburg gets back on track with a sublime outing Friday, delivering seven shutout innings to go with 11 strikeouts on a season-high 109 pitches. (Mitchell Layton/Getty Images)

As soon as the ball hissed off his bat, Bryce Harper tore down the first base line on a mission. The ball bounced off the scoreboard in right field and Harper flew around the bases. He turned his head back for a quick peek at the ball lying on the warning track dirt, but he never broke stride. By the time he slid headfirst into third base Friday night in the Washington Nationals’ rain-delayed 11-1 win over the San Diego Padres, his helmet was already off.

“I was chugging it out of the box thinking three,” he said.

Harper beat the throw to third base but his left thumb jammed when it hit the bag. He popped up on one leg and slapped his hands together in celebration. Then, he reached for his hand. In the midst of a career night, Harper left after the following inning, replaced in left field by Nate McLouth because of a badly swollen left thumb.

Manager Matt Williams and Harper both said they were unsure how much rest the thumb would need. Williams said the results of an X-ray were negative. At first, the injury looked more severe than a jammed thumb based on Harper’s grimace holding his hand after the slide. But afterward, he said he had a feeling the thumb injury was simply swelling-based. Harper, whose thumb and hand were heavily taped up after the game, will be reevaluated on Saturday.

“I went out there to the outfield, swelled up a bit,” he said. “I thought we were in a good spot and Matt did, too. Got in, got some treatment on it.”

Harper’s breakout night — a career-high four RBI capped by his thrilling bases-clearing triple — propelled the Nationals to victory a day after a head-scratching offensive futility in a loss. Stephen Strasburg was staked to an early lead and fired seven spectacular innings, striking out 11. The Nationals went 7 for 17 with runners in scoring position. They produced a season-high 17 hits and torched the Padres’ strong pitching, led by Anthony Rendon’s career-high four hits.

“We’ve got a great lineup and we’re missing Willy [Ramos] and [Ryan Zimmerman],” Harper said. “I think where we’re at right now swinging the bat, I think everybody needs to just keep it going, and we’ll keep going every day.”

For much of the first month of the season, Harper has toggled between being productive and slumping. He began the season in a small funk, emerged from it with a relaxed approach at the plate and then fell into another small funk. It coincided with his benching last week by Williams for not running out a ground ball. Harper’s play this past week — such as a two-strike bunt attempt with no outs and a runner on base, and a half-jog, half-run down the first base line — raised some questions.

But on Thursday, Harper smacked two hits. A day later, he broke out. He entered the game with five RBI in his previous 21 games. By the third inning, he set a career-high mark. The Nationals took a 2-0 lead in the first inning thanks to an opposite-field RBI double by Ian Desmond and an RBI single by Harper. Six batters into his start, Padres left-hander Robbie Erlin fielded a mound visit from a coach.

The Nationals made Erlin even more miserable in the third inning, a four-run frame capped by Harper’s hit. Rendon singled, Adam LaRoche drew his 15th walk of the season and Desmond singled to load the bases. With one out and facing a full count against Erlin, Harper crushed a fastball to right field and took off. Now, Harper may have to rest with a hurt thumb, halting his offensive surge.

“It [stinks],” he said. “But I feel like my swing is where it needs to be. I feel good, am staying on a lot of pitches and having good at-bats. Hopefully I come in [Saturday] and it feels pretty good.”

Without Harper the Nationals added four more runs. Jose Lobaton continued his surge with three hits. LaRoche, the team’s most consistent hitter this season, added an RBI double and scored two runs. Slumping of late, Desmond drove in two runs. But even one run would have been enough for Strasburg.

Even though he faced a feeble lineup, Strasburg made the Padres look silly at times. He struck out the side in the second inning, featuring a wicked change-up and a curveball that broke as if it was sucked into a vacuum cleaner. His command was sharp and he kept his offspeed pitches low in the strike zone.

“I’m just trying to make quality pitches and not necessarily be over aggressive by throwing the heater down the middle and challenging them,” Strasburg said. “I’m just trying to make my pitches from first pitch on.”

Added Lobaton: “There was a lot of pitches I didn’t move the glove.”

After six innings, Strasburg’s pitch count sat at 101. The bullpen carried a heavy load in Thursday’s 12-inning loss and Strasburg provided relief a day later. He emerged from the dugout for the seventh inning and returned to it after firing only eight pitches in his final frame.

“That’s the learning curve, I think,” Williams said. “He knows where he’s at pitch count wise. And he knows that his pitches are probably limited in that inning anyway. So he went right after them. He threw even more fastballs in that last inning than he had in the previous inning.”

The Nationals needed a strong starting performance and Strasburg delivered. He allowed seven hits and walked two. With his 11 strikeouts, he became the major league leader with 53. With an offense surge behind him, Strasburg helped the Nationals secure a victory, even with only four innings of Harper.