Evan Gattis made it to the big stage for the first time Wednesday, and the Braves rookie delivered a smashing performance.

A week after Gattis, aka El Oso Blanco, called making the opening-day roster the high point of his life so far, the big Texan topped it with a home run off Roy Halladay for his first hit in his major league debut, a 9-2 win against the Philadelphia Phillies at Turner Field.

“There’s no (words) to explain it,” said Gattis, who led off the fourth inning with a home run in his second plate appearance. “I’m glad I got that one out of the way. Couldn’t have planned it. Just excited. Happy. Little emotional after the game.”

Justin Upton hit his second homer in as many games in the first inning, and the Braves rolled over the Philadelphia on a cold, rainy night before an announced crowd of 24,289, improving to 2-0 to start the season. Paul Maholm allowed six hits in 5 2/3 scoreless innings, with one walk and six strikeouts.

Jason Heyward added a two-run homer off Jonathan Papelbon in the eighth for the Braves, who’ve hit six homers and outscored Philadelphia 16-7 in two games.

“Those guys in the lineup, they’re going to torture pitchers,” Maholm said of the Braves. “They’re going to have nights where they don’t, but I’ll take this lineup over any other.”

Halladay had nine strikeouts in just 3 1/3 innings, but was charged with six hits, five runs and three walks and gave up homers to Upton and Gattis. He threw 95 pitches (55 strikes) to get 10 ounds. Upton’s two-run homer fueled a three-run first inning, and Gattis hit a leadoff homer in the four-run fourth.

Gattis was the seventh Brave to homer in his major league debut since the team moved to Atlanta in 1966 and third to do it in four years, after Jordan Schafer in 2009 and Heyward in 2010.

“That’s awesome, man,” Heyward said. “I’m really happy for him. Roy Halladay’s not a bad one to have your first home run off of. But I’m also glad we won in his first home-run game. I feel like he did a good job behind the plate, too, calling a pretty good game, clearly, with (Maholm).”

Freddie Freeman drove in the other three runs in the fourth with an opposite-field, bases-loaded double against left-hander Raul Valdes, giving him consecutive three-RBI games to begin the season. Freeman had three hits in the Braves’ 7-5 win Monday, including one of three homers off lefty Cole Hamels.

“Any time we can jump out in front of a pitcher like Halladay, it’s a plus for us,” Upton said. “It gives Paul a chance to settle in and got his stuff going and we kind of tacked on from there…. It’s fun. The team starts 2-0 and we keep swinging the bats. It’s always fun when that happens.”

Gattis bought 13 tickets to the game for friends, former coaches and family members, including his dad, Jo, who was being interviewed on Fox Sports South’s game telecast when Gattis homered. Some relatives were supposed to return to Texas on Tuesday, after seeing the opening-night game that Gattis didn’t play in. But they all made arrangements to stay another day after finding out he would catch Wednesday.

“All the people that have helped me along the way, I can’t thank them enough,” Gattis said. “I’m glad they got to come. I’m glad they wanted to come. It’s just too cool.”

His homer to left field thrilled his personal cheering section and most of a crowd that hoped to see the buzzed-about phenom do something memorable.

“Did you guys think anything else was going to happen? It didn’t surprise me one bit,” Braves manager Fredi Gonzalez said. “He did a nice job catching, too. I was hoping he would be able to get a base hit and catch a shutout his first major league game, but that didn’t happen. He did a nice job.”

Gattis picked up his nickname El Oso Blanco — Spanish for The White Bear — while leading the Venezuelan league in homers and slugging percentage this winter. Now he’s working on a new chapter to a remarkable story that began when he walked away from a Texas A&M scholarship without ever attending, instead going for a stint in drug rehab.

The 235-pound catcher vowed never to play baseball again after injuring a knee in junior college. He spent nearly four years out of baseball, wandering the western United States while doing odd jobs from janitor to ski-lift operator, while seeking spiritual advisors and new-age philosophers who might help him find some deeper meaning to life.

He stopped when he realized he didn’t need to look anymore, that he was ready to just live. And play baseball again.

Drafted in the 23rd round out of Texas-Permian Basin in 2010, Gattis hit .308 with 44 homers in 832 at-bats in 2 1/2 minor league seasons (none above Double-A) before making the team as a non-roster invitee with a resounding performance in spring training.

Coincidentally, his home run ball was caught by Bryce Kammeyer, a Texas A&M alum. Kammeyer showed a text he sent to a friend before the inning, when he said he was going to go out to the left-field seats in case Gattis hit homer. “Good plan, the friend texted back.

Kammeyer gave Gattis the home-run ball in exchange for a handshake and another autographed baseball.

“He was from A&M, which is kind of funny,” Gattis said.

Gattis will share catching duties with veteran backup Gerald Laird until starter Brian McCann returns from the disabled list, probably in late April or early May. At that point the Braves could carry Gattis as a third catcher/fifth outfielder and right-handed pinch-hitter. If he keeps hitting, chances are he’ll stick around.

The Braves’ first two games have featured the type of offense most expected from this revamped lineup — a lot of power, plenty of runs, and many strikeouts (24 in 16 innings). Their 16 strikeouts Wednesday included four by Upton’s older brother, B.J., who struck out in every plate appearance for a “golden sombrero” in his second game as a Brave.

Through four innings Wednesday, Braves hitters had seven runs, two homers and 11 strikeouts. Halladay, who doesn’t throw nearly as hard as he once did, had one of the more unusual stats you’ll see — nine strikeouts in 3 1/3 innings.

Halladay went 4-1 with a 1.78 ERA in his first seven career games against the Braves, but is 0-3 with an 11.57 ERA in five starts against them since the beginning of 2012. He has allowed 36 hits, including eight homers in 22 innings in those five.

Heyward was asked if it seemed liked the same Halladay he faced in the past.

“Not velocity-wise,” Heyward said. “But again, he has a lot of weapons. I feel like it’s no surprise to see the strikeouts. Once he gets two strikes on you, he can go whichever way he wants and pick. But we did wear him down some and got some pitches to hit, and we hit them hard.”

The Braves are 13-4 against the Phillies dating to July 6, and scored six or more runs in nine of those 17 games. Freeman is 13-for-28 with three homers and 11 RBIs in his past eight games against the Phillies.