Oswalt asked Berkman to a bullpen session late last week for advice and on Tuesday the Astros ace looked like his old self and got his first win in almost a month, a 6-1 victory over the Milwaukee Brewers.
It didn't hurt that along with his helpful hints and pointers, Berkman also homered and hit a three-run triple in the win.
"I got him to stand in and he told me to do a few things different and it worked out," Oswalt said. "It helped out a lot."
Berkman said his advice wasn't anything major, but that it simply helped to have a fresh set of eyes looking at Oswalt's pitches.
"After standing in there I just said: 'Look, your stuff is awesome, don't reinvent the wheel. You don't have to come up with some new breaking pitch, just go with what you've won over 100 games with,'" Berkman said.
"It looked like he was a little more of his aggressive self tonight and threw the ball with confidence."
Berkman's 19th homer of the season landed in the left-field Crawford Boxes and scored Miguel Tejada to give Houston a 2-0 lead in the first. Berkman is second in the majors in home runs behind Philadelphia's Chase Utley and is the leader in runs scored (61) and extra base hits (45).
He pushed Houston's lead to 6-1 in the seventh inning with his bases-clearing triple to give him a season-high five RBIs. The ball sailed over the head of Milwaukee's Mike Cameron and rolled to the top of Tal's Hill in center field to score Brad Ausmus, Darin Erstad and Kaz Matsui.
Brewers manager Ned Yost defended Cameron's work on the play.
"He didn't misplay it," Yost said. "It was a tough play. He's a Gold Glove outfielder. If he misses that nobody catches it. It was hit hard. It had a lot of backspin and it just kept rising."
Berkman, who also had a single, is hitting .379.
Oswalt (5-6) broke a three game losing streak with his first win since May 12. He allowed five hits and one run with a season-high 10 strikeouts.
Ryan Braun's home run to right field in the third inning made it 2-1.
"He was nasty," Braun said of Oswalt. "His fastball was exploding. That's the best I've ever seen him. He was on top of his game."
After the homer, Oswalt retired 11 of the next 12 batters, before Bill Hall doubled with one out in the seventh inning. After the hit, Oswalt got Jason Kendall and Hernan Iribarren out to get out of the inning.
Asked if this was Oswalt's best performance of the season, Astros manager Cecil Cooper replied: "Without question. I thought he threw the ball exceptionally well tonight."
"He was vintage Roy tonight."
Michael Bourn singled in the bottom of the seventh for the Astros before Ausmus reached on an error by pitcher Julian Tavarez. Tavarez bounced the ball in the dirt near first base to allow Ausmus to reach safely.
Pinch-hitter Erstad followed with a run-scoring single that pushed Houston's lead to 3-1.
Brewers starter Seth McClung (3-3) allowed three hits and two runs in six innings. He walked one and struck out five. He has been ill with a stomach virus for the last few days and said he threw up after the third inning and after the game.
Iribarren was recalled from Triple-A Nashville on Tuesday. ... Oswalt continued to be strong against Prince Fielder, who went 0-for-3 on Tuesday and is 4-for-28 with seven strikeouts against Oswalt in his career. ... Bourn extended his career-high hitting streak to six games on Tuesday.