SEATTLE -- Michael Harris II was promoted from Double-A Mississippi to stabilize the Braves’ outfield defense, which was a liability before his arrival. A little more than three months later, the young center fielder stands as a key reason Atlanta is back atop the National League East standings.

Harris continued to be a difference-maker as the Braves claimed a 6-4 win over the Mariners on Friday and gained sole possession of first place in the NL East for the first time this year. The young outfielder highlighted the series-opening win with a hustle double and an impressive opposite-field home run.

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“He’s a fun watch and he’s a lot of fun to be around,” Braves pitcher Charlie Morton said. “He’s generally pretty quiet, but he’s still an integral part of the clubhouse with his energy and his personality. Then the talent, it’s just ridiculous.” 

With their eighth straight win, the Braves moved a half-game in front of the Mets, whose Friday night loss in Miami moved them out of first place for the first time since April 11. Atlanta moved into a tie for first place on Tuesday night, but fell back when New York swept a doubleheader in Pittsburgh on Wednesday.

When Harris was called to the Majors on May 28, the Braves were 7 1/2 games back and in need of a center fielder who could create some stability in the outfield. Four games into his career, Atlanta was 10 1/2 games back. But the defending World Series champions have since gone 64-24.

“It shows how dedicated we are to winning and how much we want to win,” Harris said. “We were down 10 games at one point, and now we’re leading the East. That was our main goal. We got to it, and now we’re just trying to keep it.” 

It’s no coincidence the Braves have surged since the arrival of Harris, who has hit .312 with 16 homers and an .897 OPS through his first 91 games. Atlanta’s 21-year-old breakout star has become widely respected, but maybe not as widely recognized as Mariners rookie center fielder Julio Rodríguez, who has hit .271 with 23 homers and an .811 OPS and took center stage at the Home Run Derby.

Harris spent most of the past few months as MLB’s youngest player (now second youngest behind the Orioles’ Gunnar Henderson) and this is just his second full professional season. But he seemed to arrive on the scene with confidence and aggression, which he showed when he turned a single into a double to begin the fourth inning. His nifty slide positioned him to score on Robbie Grossman’s RBI single.

“I like using my speed to my advantage,” Harris said. “That was one of those times where it was a good time to do it.”

Harris also opened the sixth inning with a homer that easily cleared the left-field wall. The 369-foot shot was the longest opposite-field homer hit by a left-handed hitter at T-Mobile Park this year. It was just another example of the pure power possessed by the young slugger, who has hit nine of his 16 homers to straightaway center or to the opposite field.

“When he hit the ball the other way, that’s just crazy to me, watching him do that,” Braves manager Brian Snitker said. “My God. He can beat you with all the tools -- with his arm, his legs and his power. He keeps blowing me away.”

Despite not debuting until May’s final week, Harris entered Friday leading all rookie position players with a 4.2 WAR, according to FanGraphs’ metric. The only rookie with a higher fWAR was Braves right-hander Spencer Strider (4.4).  

Time will tell whether Harris or Strider wins the NL Rookie of the Year Award. But for now, both are committed to helping the Braves capture a fifth straight division crown and a second straight World Series ring. 

“This is a really, really good clubhouse and [Harris] has been such a great part of it,” Morton said.