SAN DIEGO - Sometime around 4 p.m. yesterday afternoon, Antonio Bastardo strode into the visitors' clubhouse at Petco Park with the walk of someone who had been there before. His eyes shaded by a pair of designer sunglasses and his ears muffled by a pair of headphones, he appeared lost in that world where a starter disappears in the hours before he takes the mound.

With one tap on the shoulder, however, the mirage disappeared. Phillies assistant general manager Scott Proefrock motioned to him, and Bastardo dutifully followed into an adjoining room, where, quite literally, there were some I's to dot and T's to cross. After all, you can't get paid if you don't sign your big-league contract.

Legal documents aside, there wasn't much of an indication last night that Bastardo was making his third start above Double A, not to mention his major league debut. Although he was aided by a four-run first inning that sent ailing Padres ace Jake Peavy to the earliest exit of his career, the 23-year-old lefthander exceeded any realistic expectations in the Phillies' 10-5 win at Petco Park.

From the confident stride he displayed while pacing the mound to the fastball that arrived at the plate between 91 and 95 mph, Bastardo did not appear the least bit fazed in his first bout with a big-league lineup. He allowed one run on four hits in six innings, striking out five and walking one while giving his teammates the ability to withstand the four-run seventh inning that the Padres posted against righthander Chan Ho Park.

"I didn't think about my big-league contract or anything like that,'' Bastardo said through a translator. "I really was trying to focus on another start and what I had to do, the job I had to do.''

"He did a super job,''manager Charlie Manuel said with a grin, "but he did it with one pitch.''

Bastardo attacked hitters and threw strikes. And presumably, he earned another start in the rotation spot formerly occupied by Brett Myers, who likely will be lost for the season when he undergoes hip surgery tomorrow in New York.

Granted, one start is not grounds for a judgment, particularly not a start like last night, when Bastardo was able to rely heavily on his fastball in a game the Phillies led 6-0 heading into the bottom of the third. His lone hiccup came with one out in the sixth inning, when Padres first baseman Adrian Gonzalez sent a 1-0 fastball screaming off the seats in rightfield for a solo home run. But he had close calls on a couple other occasions, including the first inning, when Scott Hairston crushed a would-be, two-run home run to left that bounced off a billboard just a few feet to the left of the foul pole.

All thing considered, however, it was an impressive debut, particularly from the perspective of a man like Sal Agostinelli. The Phillies' international scouting supervisor, Agostinelli watched Bastardo's debut from a restaurant in the Dominican Republic, where 5 years earlier he had followed up on the recommendation of organization scouts Wilfredo Tejada and Bernardo Perez and signed the stocky lefthander to a $17,000 bonus.

Bastardo joined the Phillies' summer-league team in the D.R. in 2005, where he went 2-2 with a 2.13 ERA. Over the next 3 years, he would spend time in Clearwater, Lakewood and Reading, excelling at each stop. After watching him in spring training this season, the organization briefly tried to turn Bastardo into a reliever, thinking he might be able to provide a stop-gap replacement for suspended lefty specialist J.C. Romero if the need arose. But they scuttled that plan after only four relief appearances and sent him back to the rotation. After five starts, he earned a promotion to Triple A Lehigh Valley, where he pitched so well (1-0, 2.08 ERA in two appearances) that the Phillies tapped him to fill in for Myers.

"He's got such a good arm," Agostinelli said. "His arm is electric. He just needs to get the breaking ball going and use the changeup a little more."

His ability or inability to use his off-speed pitches effectively could decide whether his current presence on the big-league roster develops into a more permanent home. He won't always have the backing of a ferocious Phillies offense, which last night got two home runs and a season-high five RBI from leftfielder Raul Ibanez on his 37th birthday and a solo home run and two RBI in a rare start by third baseman Greg Dobbs. The Phillies (30-20), who won their fifth straight game and improved their lead in the National League East to 2 1/2 games, have hit five home runs in two games at the normally pitcher-friendly Petco Park.

Ibanez, who hit his 200th and 201st career home runs, has 19 homers and 51 RBI.

"I feel blessed,'' he said in a postgame television interview on CSN. "These guys are always on base. You're only as good as your teammates.''

Ibanez couldn't help but be impressed by Bastardo.

"When I started looking up there and he was pumping 94, 95 [mph] and it looked like it was cutting, moving all over the place - I knew he had a good arm, but I didn't know he had that good of an arm,'' Ibanez said.

It was difficult not to be impressed with Bastardo, especially on a night in which he outlasted a former Cy Young winner - albeit one suffering from both a tender ankle and the flu - who many fans would love to see land at One Citizens Bank Way. Peavy, who has a no-trade clause and is an extreme longshot to join the Phillies, was replaced by Josh Geer before the second inning.

It was a day of firsts: first appearance, first start, first win.

And, yes, first big-league contract. Right now, it looks like he'll be abiding by its terms for at least 6 more days. *