Nationals relief pitcher Sean Doolittle earned the save on Tuesday against the Angels. Edwin Jackson earned the win after pitching seven strong innings. (Chris Carlson/AP)

Gio Gonzalez and Tanner Roark ambled into Angel Stadium on Tuesday afternoon, flanking a man with a Washington Nationals duffle bag on his shoulder who looked much younger than either of them but was older than them both.

Edwin Jackson, 33, had not carried a Nationals bag since 2012, a half-decade and a baseball lifetime ago. But the Nationals need a fifth starter, and Jackson can unpack his bag for the time being. After he threw seven strong innings in the Nationals’ 4-3 win over the Los Angeles Angels on Tuesday night, he will get a chance to stay.

“As far as I’m concerned, he’s our fifth starter,” aspiring general manager Bryce Harper said.

“Oh yeah,” Dusty Baker said. “ . . . I don’t think that’s a question.”

Jackson seized Tuesday’s opportunity with seven innings in which he allowed two runs on three hits, two of which were solo home runs, one of which was golfed out by Mike Trout. He did not walk a batter, thereby avoiding the one thing that has scuttled his career as many times as his stuff has salvaged it.

“My biggest thing has always been walks, walks, walks, behind in the count and walks — and then you get a big hit,” Jackson said. “I’ve just been trying to focus on coming out and putting an attack on hitters and make them put the ball in play.”

Jackson did that, and was not the only National to impress on his first day, as newly acquired relievers Ryan Madson and Sean Doolittle were immediately deployed to hold a one-run late-inning lead in their first Nationals outings. Madson threw a 1-2-3 eighth inning. With a run of insurance courtesy of Adam Lind’s ninth-inning homer, Doolittle earned his first Nationals save despite allowing a walk, a hit, and a run and facing Trout and Albert Pujols with the tying run aboard.

Before the game, a hopeful haze hovered over the Nationals, like it does over Orange County on summer days like this, a cloud of near-chaos created by the arrival of those two long-awaited relievers and the return of the respected former starter.

That haze obscured the spotlight that dropped onto Angel Stadium this week like a once-a-decade comet for a rare meeting between two of baseball’s shining stars, Bryce Harper and Mike Trout. Harper and Trout, the 2012 rookies of the year, have three MVPs and 11 all-star selections between them. Nothing could overshadow them for long.

In his first at-bat of the series, Harper homered, a deep flyball to left-center that snuck just over the wall and Trout’s leap. In his first at-bat of the series, Trout homered, a deep flyball to left-center, a few yards farther than Harper’s shot.

After that, Jackson maneuvered through a barrage of hard-hit balls early, then settled in after second baseman Daniel Murphy headed to the mound to tell him simply, “make them earn their way.”

“That little comment kind of got me locked in,” Jackson said. “And [catcher Matt] Wieters and myself were kind of able to get into a rhythm after that.”

Jackson carried more than a decade of improbable baseball ups and downs with him to his latest big league locker on Tuesday. Jackson has played for 12 teams, including the Angels, and been traded six times.

He once led the league in losses. He was an all-star in 2009. Memorably, he once threw a no-hitter in which he walked more men than he struck out. Jackson was traded for Max Scherzer in the deal that brought Scherzer to Detroit, was once traded in a deal with former Nationals pitcher Marc Rzepczynski, was once traded for ... well, you get the picture.

“I’ve been through my ups, I’ve been through my downs. I’ve been in Triple-A, I’ve had people asking me why am I still here, why am I still playing,” Jackson said. “ . . . Why don’t I just go home and enjoy the family? But I still feel like I have something in the tank. And I still feel like I don’t have anything to prove to anyone else, I still have something to prove to myself.”

Jackson entered Tuesday with 114 career losses, eighth-most among active pitchers — a stat that perfectly represents the nine lives an electric fastball and sneaky slider can earn a man. He left with his 94th career win, because after homering and singling twice, Harper tripled to lead off the top of the eighth. He scored on Ryan Zimmerman’s single up the middle, thereby creating the kind of one-run lead these Nationals dreaded throughout the first half.

But the relievers they acquired to expel that dread did so Tuesday night, Madson uneventfully, Doolittle a little more eventfully. Both men admitted debut-like nerves, but Doolittle was the only one to succumb for a time, walking the leadoff man then allowing his first hit to a left-handed hitter all season — a ringing double to Kole Calhoun that helped lefties improve to 1 for 25 against him this season. But he got Trout to ground out, then Pujols to fly out weakly, stranding the tying run at second to end the game.

“I promise they won’t all be like that,” said Doolittle, whose adventure did not preclude him from locking down the Nationals’ sixth straight win and fifth in five games since the All-Star Break. None of the three pitchers who pitched for them was on the roster before that break. All three seem likely to factor significantly in the weeks that follow.