Braun delivered a tiebreaking RBI single in the 11th for his fourth hit, leading the Brewers to a 9-8 victory on Saturday.
"I never thought it was over, never, not until the last swing and miss," Milwaukee manager Ken Macha said. "Look at your research on that team, the Astros lineup. They haven't scored a lot of runs but I never felt the game was over regardless of what the lead was."
Prince Fielder homered twice, including a two-run shot in the ninth that gave Milwaukee an 8-7 lead, and Bill Hall drove in four runs with a three-run drive and an RBI single. But Hall's throwing error in the bottom of the ninth allowed the Astros to tie it.
"Obviously I had a play that I should have made but I didn't have the best footing and that's why I didn't get off the best throw," Hall said. "I've been playing great defense so I'm not going to beat myself up over it. I'll depend on what I do all season long."
Corey Hart led off the 11th with a double against Geoff Geary (0-3), the last of five Houston pitchers. That set the stage for Braun, who is batting .474 with four homers and 11 RBI in his last 10 games.
"It was a great baseball game, fun to be a part of and obviously a lot more fun because we ended up winning," Braun said. "I've slowed everything down. I'm dictating the pace instead of letting the opposition do it. I knew eventually I'd go on a streak like this."
Mark DiFelice (1-0) pitched 1 1/3 innings for the victory. He struck out the last two batters in the 11th to give the Brewers their fourth straight win.
"He's a strike throwing machine," Macha said. "That's what he does. I looked up there one time and he'd thrown eight pitches and they were all strikes. You've better be ready to hit. He's got good movement on his fastball. It cuts across the zone and if you haven't seen him, it's tough to realize what the ball's going to do."
Astros manager Cecil Cooper and catcher Ivan Rodriguez were ejected in the eighth inning after Rodriguez took issue with plate umpire Mark DiMuro's strike zone.
"We showed some fight and continued to fight hard," Cooper said. "We have to make some better pitches. A lot of those pitches were bad pitches. They were not in the right spot. Particularly from my bullpen. We've done this over and over during these first 18 games. They got to get something fixed. We gave up eight runs in the last five innings. We can't let that happen. We have a good bullpen."
The Astros tied it at 8 with two out in the ninth when Hall threw wide to first on Hunter Pence's grounder, allowing Lance Berkman to score.
After Pence reached second on a passed ball, Carlos Villanueva intentionally walked Geoff Blum. J.R. Towles then grounded out to send the game to extra innings.
The lead bounced back and forth and the mood got intense in the eighth with the game tied at 4. Rodriguez was ejected by DiMuro after he protested a ball call with LaTroy Hawkins pitching to Mike Cameron. Then, Cooper charged the plate and was tossed.
Towles, who arrived earlier in the day from Triple-A Round Rock, hustled into his catching gear to replace Rodriguez, who continued to scream at DiMuro all the way to the dugout.
Hall singled in a run and Jason Kendall hit a sacrifice fly during the hectic eighth inning, helping the Brewers grab a 6-4 lead.
The Astros erased the deficit with three runs in the bottom half. Towles had an RBI single and Kaz Matsui added a two-run double.
Carlos Lee and Michael Bourn homered for Houston, which led 4-1 after five innings. Mike Hampton allowed four runs and eight hits in six innings.
Jeff Suppan gave up four runs, three earned, and four hits in six innings for Milwaukee.
The Astros placed C Humberto Quintero on the 15-day disabled list with a strained right shoulder. ... Cameron needs five home runs to join the 250-250 club for homers and stolen bases in a career. He has 291 steals. Only 19 players in major league history have reached the 250-250 milestone.