ATLANTA -- With Drew Smyly constructing his most impressive start of the season, Ronald Acuña Jr. needed just one swing to give the Braves a series win, heading into their most important stretch to date.

Acuña’s 100th career homer was enough to back Smyly, who flirted with a seven-inning no-hitter while guiding the Braves to a 1-0 win over the Cardinals in the second game of a doubleheader on Sunday night at Truist Park.

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“This was a good series to win, a big series to win, because we have a grueling week coming up,” Braves manager Brian Snitker said. “The Reds are playing really good and the Mets are obviously playing really good. So, it’s going to be a tough week.”

But thanks to Acuña’s one-out, third-inning homer off Kwang Hyun Kim, it’s a week the Braves will enter with optimism. By taking three of four from the Cardinals, they have distanced themselves from consecutive disheartening losses against the Red Sox last week.

“Spirits are high and the energy is up,” Acuña said through an interpreter. “I think we’re just looking forward to carrying that into New York and winning that series.”

The Braves entered this four-game series against the Cardinals having lost six of seven. But they will enter a four-game series against the Mets on Monday still just five games back in the National League East standings. It’s not where they want to be. But they’re in a better place than they were earlier in the week and earlier Sunday, when Adam Wainwright’s three-hit shutout led the Cardinals to a 9-1 win in the first game of the twin bill.

“We know where we are at as a team,” Smyly said. “We’ve got a big series coming up. The Cardinals are a great ballclub. So, to be able to take three of four, that gives us some momentum going into this road trip. Everybody knows we need to try to get it rolling.”

One way to get on a roll is to consistently get strong efforts from the starting pitchers. Charlie Morton carried a no-hit bid into the seventh inning of Thursday’s series opener and Max Fried allowed two hits over seven scoreless innings on Friday. Smyly followed their lead by allowing just one hit over 5 2/3 scoreless innings in the series finale.

Smyly’s no-hit bid ended when Paul Goldschmidt recorded a two-out single in the sixth. Braves second baseman Ozzie Albies was shaded behind the second-base bag before he ranged to his left to field Goldschmidt’s grounder at the edge of the grass. Albies’ attempt to produce a defensive gem evaporated when his throw pulled Freddie Freeman off the first-base bag.

“I knew it was a seven-inning game, so I wasn’t really thinking about [throwing a no-hitter],” Smyly said. “It would have been cool if you did. But it’s not like it matters in a seven-inning game. I was just trying to keep guys off base and hold onto the lead.”

After bidding adieu to a potential seven-inning no-hitter, Luke Jackson and Will Smith combined to preserve the lead that came courtesy of Acuña’s 19th homer of the season. The solo shot narrowly cleared the left-center-field wall.

“You expect him to hit a home run or do something awesome every time and that's not even fair to him because it's not possible,” Smyly said. “But he's that type of player where every time he comes up, you're waiting for something awesome to happen. He's pretty fun to watch. These Braves fans shouldn't take him for granted, because he's a special player.”

Acuña's 100th homer comes in his 378th game. The only players to reach this milestone in fewer games were Ryan Howard (324), Gary Sánchez (355), Aaron Judge (371), Ralph Kiner (376) and Joey Gallo (377). It was also the fastest any player has gotten to both 100 homers and 75 stolen bases, by number of games.

In terms of age, Acuña hit this 100th homer when 23 years and 184 days old. The only players to reach the century mark at a younger age were Mel Ott, Andruw Jones, Eddie Mathews, Alex Rodriguez, Tony Conigliaro, Miguel Cabrera, Johnny Bench and Bryce Harper.

“Congratulations to him on his 100th homer,” Snitker said. “That’s a big milestone for a kid that young. He’s going to have a few more of those hundred-homer milestones in his time.”

According to STATS by STATS, Acuña became the first NL player to hit a milestone home run in a 1-0 victory. This particular solo shot allowed the Braves to also halt their maddening futility in home doubleheader games this year. Though the Braves tallied just four hits in this latest nightcap, thanks to Smyly and Acuña, one would have been enough.

“It's always great to hit a home run,” Acuña said. “But there's no better feeling than to hit a home run and putting your team up.”