Sean Newcomb walked the leadoff batter in three of his six innings Sunday against the Marlins. A year ago that might have been a recipe for disaster for the Braves’ imposing young left-hander.

But Newcomb has come a long way in less than a full season in the majors.

He showed that again by not letting any of those innings spiral on the way to six scoreless innings of one-hit ball in the Braves’ 4-3 series-clinching win, extending his streak to 20 scoreless innings over three starts.

“Every time I got into a little jam and put somebody on base, I just kind of slowed it down a little extra, focused on one pitch at a time and just made sure I was executing,” said Newcomb, 24, who didn’t have his best command but allowed only one hit, his low in 27 major league starts.

Newcomb has given up just five hits in 20 scoreless innings while winning his past three starts, all on the road. He has eight walks and 20 strikeouts in those outings against the Mets, Rays and Marlins.

“In his first full year -- that’s very impressive,” Braves manager Brian Snitker said of the scoreless streak. “I thought he was a little erratic with his fastball command (Sunday), but again the change-up helped him, and I thought he had some big-pitch curveballs that helped him out. He just kept pitching, kept working. A year ago, that game probably gets away from him. But right now he’s got more weapons, more experience.”

After allowing five hits and five earned runs in 4-1/3 innings of his season-debut loss against the Nationals, Newcomb is 4-0 with a 1.70 ERA and .182 opponents’ average in his past seven starts. He’s recorded 48 strikeouts with 18 walks and allowed only three home runs in 42-1/3 innings in that period and the Braves have won five of those seven games and each of his past four starts.

“He’s been unbelievable,” Braves center fielder Ender Inciarte said. “Every time he’s on the mound it’s quick outs, he’s pitching with great momentum. We’re back in the dugout in no time. It’s great for us to play defense for a couple of minutes and go back to hitting right away. He’s been great for us since Day 1.”