Ronald Acuña Jr. provided a powerful spark and Will Smith made a successful season debut as the Braves claimed a 5-2 win over the Phillies in the first game of a seven-inning doubleheader on Sunday afternoon at Citizens Bank Park.

Acuña's two-run homer off Deolis Guerra in the fifth inning snapped a 13-inning scoreless streak and gave the Braves a lead they would not squander. His second homer of the season keyed a five-run fifth that was supported during what was essentially a bullpen game.

• Box score

The Braves pulled Huascar Ynoa out of the bullpen to make his first career start. Ynoa navigated the lineup once while filling the role of an opener. The 22-year-old prospect completed the first two innings in perfect fashion and watched Tyler Matzek minimize the threat he inherited in the third.

"Honestly, when we started, I was thinking two innings out of Ynoa," Braves manager Brian Snitker said. "He hadn't been out there. He started to get tired, missing arm side. But he did a great job."

Here are three key moments from the Game 1 victory:

Acuña's blast
As this season approached, there was reason to debate whether Acuña could produce a 20-20 season. Last year, he became just the fourth player over the past 25 years to hit 20 homers and record 20 stolen bases within any 60-game stretch.

But with more than one quarter of this season complete, Acuña has hit just .217 with two homers and one stolen base. Still, this most recent homer was a significant one. His two-run shot off Guerra snapped Atlanta's 13-inning scoreless streak and fueled what became a five-run fifth.

Acuña slumped through the season's first week, but he entered Sunday's second game having hit .281 with four doubles, two homers and a 1.019 OPS over his past nine games.

"He's up and down now, and battling to get consistent and be where he wants to be," Snitker said. "But I see improvement. He's working. That kid set the bar so high. As long as he keeps working at it and gives himself a chance, he's going to be just fine."

Reliable 'pen
Though he was asymptomatic, Smith spent all of Summer Camp on the COVID-19 injured list and was not activated until Thursday. Still, Snitker felt confident to ask the All-Star reliever to begin his season by facing Bryce Harper with a runner on, two outs and the Braves holding a 5-2 lead in the fifth, which was essentially the seventh in this shortened game.

Harper walked, but Smith killed the threat by getting Didi Gregorius to pop out. The veteran lefty's presence will fortify a bullpen that entered Sunday ranked third in the National League with a 2.74 ERA.

"There's never a perfect time to get a guy in that first game," Snitker said. "I felt good about him in that situation. He's been through that a lot. It was just good to get him out there, breaking a sweat on the mound."

Smith gives the Braves another closing option as he becomes one the team's top high-leverage options. He's joining a 'pen that has been fortified by the comeback story of Matzek, who returned to the Majors this year for the first time since developing the yips early in the 2015 season.

Matzek relieved Ynoa with two on and one out in the third. After Andrew McCutchen drove in the game's first run with a groundout, the lefty reliever ended the inning by striking out Harper. Matzek has worked 7 2/3 scoreless innings over his six appearances.

Left-handed hitters are 1-for-15 with six strikeouts against Matzek.

Killing lefties
After Acuña got things rolling, Adam Duvall capped Atlanta's five-run fifth with a three-run double that came off his bat at 114.2 mph, making it the hardest-hit ball by a Braves player this year, per Statcast.

Snitker opted to put Ender Inciarte back in the lineup for the first game of the doubleheader. Along with allowing Inciarte a chance to get some at-bats, it set up the chance for Snitker to have Duvall bat for Nick Markakis when the Phillies were forced to stick with Adam Morgan for at least three batters in the fifth.

Morgan surrendered a single to Freddie Freeman and walked Marcell Ozuna before allowing the double to Duvall, who has gone 7-for-13 with two doubles and a homer against left-handed pitchers this year.

"That three-batter rule can work for you, too, I guess," Snitker said.