ATLANTA -- In a pitching matchup between a seasoned MLB veteran and a rookie making his eighth big league start, it was the latter who earned the “W” in the box score.

Nationals No. 20 prospect, per MLB Pipeline, Mitchell Parker carved up Atlanta hitters while the Nationals hammered the Braves’ Charlie Morton as Washington earned an 8-4 win in Monday’s series opener at Truist Park.

Parker went 6 1/3 innings and allowed three runs on five hits as he struck out six and didn’t issue a walk. Parker has yet to allow more than three runs in a start and his ERA is now at 3.45.

“The slider was nice today, and [I was] locating the fastball well,” Parker said. “I wouldn’t say anything wasn’t working. It was great being able to attack with multiple different angles. That was enjoyable.”

Ozzie Albies tallied a single in the bottom of the first, but Parker set down the next 14 batters he faced in a row.

“[There was] just a lot of early contact and a lot of ground balls,” Parker said. “The fielders were making a lot of plays. There were a lot of fly balls. [I was] keeping the count short and pitch count down and that’s all that matters. We were attacking. The earlier we can get [the defense] back in the dugout and score some runs, good things obviously happen. I just want to keep that rolling.”

Washington provided Parker with plenty of offense as it handed Morton his worst start of the year. Morton went 5 2/3 innings, allowing a season-high eight runs on 12 hits and two walks while striking out seven. The last time Morton allowed eight-plus runs in an outing was on June 21, 2015, also against the Nats.

The Nationals, meanwhile, tallied four hits (three doubles) in the top of the first. After CJ Abrams flied out to lead off the game, Lane Thomas doubled -- his first at-bat back from the injured list -- and was subsequently driven in by Eddie Rosario. After a Jesse Winker RBI single, Nick Senzel delivered a two-run double and Parker took the mound with a 4-0 lead. All four runs in the first inning came with two outs.

Washington added a run in the second and third, and tacked on two more in the sixth to take an 8-0 lead.

“It’s huge having an early lead,” Parker said. “The hitters were great at [taking off] stress.”

“We hit the ball really well early on to score some runs,” Nationals manager Dave Martinez said. “It’s a great way to start off, especially with [the Braves]. They tend to score some runs. We got off to a good start.”

The Braves finally got to Parker in the bottom of the seventh, racking up three runs -- including an Adam Duvall two-run home run that ended Parker’s outing.

“He pitched really well,” Martinez said. “It was hot out there. We tried to stretch him out a little bit to get to that sixth inning. He kept us in the game. He did well today.”

Parker has made it through five or more innings in all but one start this season and the Nationals have won five of the eight games in which he’s started.

“I’m just trying to use the fielders,” Parker said. “All of them out there are really good. The more we use them, the deeper into games [I get] to save some bullpen arms.”

The Nationals' bullpen quelled the Braves' additional rally attempts, with Derek Law escaping a jam in the seventh after allowing an additional run. The Nationals used three relievers to cover 2 2/3 innings.

It was Parker’s third start this season in which he did not walk a batter. He’s walked just eight all season.

“That’s huge,” Parker said. “Trying to give up as few bags as possible, it’s hard to win a baseball game when you’re giving up the free bags.”

Tacking on runs after that first-inning barrage was invaluable to Martinez, especially when the Braves put up four runs in the seventh.

“At this ballpark, you have to add on runs,” Martinez said. “They’re not gonna quit. [The Braves] can score some runs very quickly. The fact that we kept pushing, we kept adding? It was awesome.”