Atlanta ? The Rocket got rocked by the rookie. Then, while Roger Clemens shuffled uncomfortably on the mound, Brian McCann emerged from the Atlanta Braves dugout for a most unexpected curtain call.

“I was just sitting back letting him enjoy it over there,” Clemens said. “What else can you do?”

McCann hit a three-run homer off Clemens in his first postseason at-bat, sending John Smoltz and the Braves to a 7-1 victory over the Houston Astros on a drizzly Thursday night, tying their best-of-five NL playoff series at one game apiece.

Smoltz picked up where he left off six years ago, pitching seven strong innings in his first October start since the 1999 World Series.

“There’s a thousand emotions going through my head right now,” he said. “I’m going to sleep a long time tonight.”

While Smoltz’s performance was a long time in the making – he spent the last four postseasons as a closer – it was hardly unexpected for someone who’s long been one of baseball’s best big-game pitchers.

Smoltz broke a one-day tie with Houston’s Andy Pettitte to reclaim the title of baseball’s winningest postseason pitcher, improving to 7-0 in the division series and 15-4 overall.

Then there’s McCann, who was batting in the playoffs for the first time when he stepped to the plate in the second inning with two on and two outs.

Atlanta catcher Brian McCann, center, celebrates with teammates. The Braves defeated the Houston Astros, 7-1, Thursday night in Atlanta to even their National League series at one game apiece.

McCann was less than three months old when Clemens made his major-league debut for the Boston Red Sox in 1984. Now, the two were face to face – a video game-playing catcher who started the season with Double-A Mississippi vs. a seven-time Cy Young Award winner who stopped off in Houston on his way to Cooperstown.

“Logic would say Roger has the upper hand in that situation,” Atlanta’s Chipper Jones said wryly.

Not this time. With Smoltz on deck, Clemens missed with his first two pitches, then left a fastball over the plate. McCann connected with a 409-foot drive that ricocheted into the Braves’ bullpen in right field for a 3-1 lead.

“A very hittable pitch,” Clemens said. “When a guy’s at this level, it doesn’t matter if he’s 21 or 41. He’s going to hit that.”

McCann was urged back on the field by manager Bobby Cox, tipping his cap to the roaring crowd after becoming the first player in Braves history (including Boston and Milwaukee, too) to homer in his first trip to the plate in the postseason.

McCann also joined Clemens in a more obscure record: biggest age gap between a pitcher and a batter who hit a postseason homer – 21 years and 200 days, according to the Elias Sports Bureau.

Another of the 18 rookies to play for the Braves this season, reliever Macay McBride, caught the home run ball in the bullpen and delivered it to McCann after the game.

“That won’t sink in for a while,” McCann said. “(Clemens) is one of the greatest pitchers of all time. He just got a pitch over the plate, and I connected. It was neat.”

With the NL East champion Braves having bounced back from a 10-5 loss in Game 1, the series shifts to Houston.

Twenty-game winner Roy Oswalt is set to go against Atlanta’s surprising 13-game winner, Jorge Sosa, on Saturday.

The Astros hope Oswalt looks better than Clemens, who led the majors in ERA (1.87) at age 43 but was bothered late in the season by a sore hamstring and also was stung emotionally by the death of his mother.