The Cubs had a 7-6 lead against Houston and runners at first and second in the Astros' seventh inning, when Luke Scott lofted a towering fly ball toward deep right.
"That ball was hit high and far, and I thought it was out of the ballpark," Cubs manager Lou Piniella said.
DeRosa, who was starting in right, had his eye on the ball all the way, and caught it over his shoulder. It could've been a perfect spiral pass.
"When he first hit it, I thought it was a homer," DeRosa said. "I just kind of tracked it and went over there and it got to its highest point and went straight down. I had a bead on it the whole time. I just didn't know what it was going to do. From [Scott's] reaction, I think he was wondering if it was going to hang fair or foul. It was another Wrigley Field game-saver there."
The east wind held the ball up just enough.
"It was hit so high, I knew I could get over there -- it was just a matter of whether it would stay in the ballpark," he said.
Did his football background help?
"I remember Glenn Hubbard, a coach for the Braves, always said, 'Just go out there and be an athlete,'" DeRosa said. "That's what I try to do. I might not do everything fundamentally sound the way it should be done, but just try to go out and make plays."
DeRosa has made the plays no matter where the Cubs put him, and that's helped the team in its successful surge. With Sunday's win, a 7-6 decision, the Cubs have won 15 of their last 19 games, and are 3 1/2 games behind the Milwaukee Brewers in the National League Central.
DeRosa has started 44 games at second, 20 at third and nine in right. And he's done well at all positions.
"He's a second baseman for us and he's so athletic," said Cubs pitcher Michael Wuertz, who picked up the win in relief. "That's the thing we all kind of marvel at because he looks so smooth out there. He's so versatile. With him out there, it gives us a lot of options."
It was an impressive catch.
"That shocked me -- this guy is pretty good," third baseman Aramis Ramirez said. "I never saw him play every day. He's pretty solid everywhere he plays."
It's the type of play that won't show up in the box score, yet made a huge difference in the game. So did Ramirez's diving catch of Carlos Lee's line drive to end the Astros fourth and strand runners at first and second.
"Those are huge," DeRosa said of the good defensive efforts. "Things are going our way right now. Hopefully, they continue."
The Cubs are playing with a lot of confidence lately.
"The amazing thing about this team right now," DeRosa said, "is that we were down, 5-0 [after the second inning] and no one in that dugout doubted that we could put five runs up on the board. We didn't expect to do it in one inning [in a six-run second], but it was nice to see Derrek Lee hit a big homer for us. He's been dying to drive some runs in and hit some balls out of the park. Hopefully, this will get him going."
Lee hit a three-run homer to highlight the Cubs' second, one of three blasts for the day. After going 10 games without a home run, the Cubs have hit four in the last two games. The offensive surge plus good pitching plus good defense is contributing to the team compiling the best record in the National League (25-12) since June 3.
"When you play a one-run ballgame, you can point to a lot of different things," Piniella said. "Give the players credit -- they're getting it done."
You can include rookie catcher Geovany Soto in that group. On Sunday, he made his second start. Houston had the bases loaded and two out in the seventh and Soto blocked two pitches in the dirt by Wuertz during Chris Burke's at-bat. Wuertz got Burke swinging at strike three.
"I've thrown to him a lot, even in Triple-A," Wuertz said of Soto. "He even said to me, 'Trust me.' I said, 'I have all the trust in the world in you.' He's great back there -- all of our catchers are great blocking balls. It's fun knowing you can bury a slider and he'll be able to catch it."
It's little things like that which are helping the Cubs.
"For any team to put a winning streak together and play the way we're playing you have to do everything right -- you have to catch the ball, you have to hit, you have to pitch, and that's what we've been doing so far," Ramirez said.
Carrie Muskat is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.