Tampa Bay's Akinori Iwamura, right, scores past Chicago catcher A.J. Pierzynski. Iwamura came home on a sacrifice fly by Willy Aybar. The Rays defeated the White Sox, 6-4, on Thursday in St. Petersburg, Fla.

St. Petersburg, Fla. ? Cool and calm, or so it seemed.

Evan Longoria and the Tampa Bay Rays appeared perfectly at home in the playoffs with a Game 1 victory over Chicago. The rookie said looks can be deceiving, though.

“I was nervous,” he said. “I think if you’re not nervous in this situation, you’re really not soaking in the moment.”

The All-Star third baseman homered in his first two at-bats, and the surprising AL East champions were a big hit in their postseason debut, beating the White Sox, 6-4, on Thursday in their AL playoff opener.

“He’s always got this way about him. He’s not going to be overwhelmed by the situation. And that speaks beyond his skill level,” manager Joe Maddon said. “Obviously, his skills are very good … and he likes these moments in a non-cocky way. He’s just very confident.”

After 10 seasons as baseball’s doormat, the Rays took the division with the best home record (57-24) in the majors. A lack of postseason experience was not a factor as they kept winning at Tropicana Field behind James Shields’ effective start and Grant Balfour’s testy, bases-loaded escape.

“It feels like you’re in a dream,” said Carl Crawford, who at 27 is the longest-tenured player in team history. “I’m just glad we got this first win out of the way. It was real special.”

Tampa Bay ranked near the bottom of the attendance charts this year, but The Trop rocked on this day with a sellout crowd of 35,041. Rays season-ticket holder Dick Vitale joined in the fun, waving a “We Love Longoria” placard from his first-row seat next to the visitor’s dugout.

Game 2 today, when Tampa Bay’s Scott Kazmir (12-8) faces Mark Buehrle (15-12).

“We want to win both of them now. We have such an advantage at home,” Longoria said.

Chicago beat Minnesota in the AL Central tiebreaker Tuesday, and took a 3-1 lead on Dewayne Wise’s three-run homer in the third inning. But Javier Vazquez, who has a history of flopping in big games, could not hold it.

Longoria became the second player to homer in his first two postseason at-bats, joining one of his former minor-league hitting coaches, Gary Gaetti, who did it with the Minnesota Twins in 1987.