Ibanez, celebrating his 37th birthday, hit two home runs, his 18th and 19th of the season and 200th and 201st of his career, and drove in five runs to back up Bastardo's outstanding pitching.
The 23-year-old left-hander from the Dominican Republic allowed four hits, walked one and struck out five in six innings. Throwing mainly fastballs, Bastardo lost his shutout bid in the sixth when Adrian Gonzalez hit his Major League-leading 22nd home run of the season.
Even before Bastardo took the mound, Ibanez, who had an RBI single, and his teammates had put a four-spot in the top of the first inning off Jake Peavy (5-6).
Peavy, the 2007 National League Cy Young Award winner, left after the first with what was diagnosed as a viral upper respiratory infection.
With Ibanez at his side, Bastardo was asked how he thought he did and whether he was nervous.
"I think I did a good job," Bastardo said through Ibanez. "I didn't think about signing the big league contract before the game. I was really trying to focus on this start and the job I had to do.
"I was a little bit nervous, but not that much," Bastardo added. "As the game progressed I felt better, more relaxed and more confident from the third inning on."
Of course by the third, the Phillies had a 6-0 lead thanks to Ibanez first homer of the night, a two-run shot off Josh Geer in the third as Geer had come on to relieve Peavy.
"When I am on the way to the ballpark, I always think about concentrating and focusing on the game at hand," said Bastardo.
As for the Gonzalez homer, Bastardo said, "I realized it was just one pitch, it wasn't a terrible pitch, but it was a pitch well hit by a good hitter."
Said Ibanez, who was 3-for-5 with three runs scored, "I was hoping that my birthday didn't leak out. We won, first and foremost, most importantly and the kid threw a great game and did a phenomenal job," said Ibanez.
That thought was echoed by Phillies manager Charlie Manuel.
"I thought he had a good fastball; he was on a rush and you couldn't slow him down if you had to," said Manuel. "He did one thing real good and that was to be aggressive and he wasn't afraid to throw the ball.
"He has a good changeup and a breaking ball, but he was gripping the ball and trying to throw it, so there wasn't much action. But he did a super job, but he did it with one pitch."
"He threw the ball a lot fast than we were told," Manuel added. "He popped a couple pitches at 94 and 95 [mph] and hung around 93-94 most of the night. He definitely went after them."
The pair of two-run shots by Ibanez marked his 11th career multiple homer game and his second this season. His first came May 16 at Washington in the first game of a doubleheader.
The Padres rallied for four runs off Phils reliever Chan Ho Park in the seventh, with Chase Headley driving in two runs on a bases-loaded single.
And in the ninth, the Padres loaded the bases on Chad Durbin and Ryan Madson came on and got the final out of the game and got his second save of the season in three opportunities.