Colorado was held scoreless in the eighth and ninth to drop the game, 6-4, and the series to the Crew.
Weiss noted that with the tying run already at second base and Braun -- one of the NL's top hitters this season with a .316 average and 22 homers -- at the plate, the decision to walk the Brewers' left fielder was the clear choice.
"I'm not going to let Braun beat us," Weiss said. "He's one of those guys that I look at and he's in scoring position when he steps in the box. I'm not ever going to pitch to Ryan Braun in a situation like that. No disrespect to whoever is hitting behind him, but the guy has been an elite player for a long time."
The pitch from Estevez that Perez hit to sink the Rockies wasn't exactly a mistake, either -- a high-velocity fastball at the knees and right off the edge of the plate.
"You don't like to give up 0-2 hits, you don't ever like to do that, but the kid's throwing 98, 99 and it's a fastball away," Weiss said. "Perez put the ball in play, it lands inside the line and ends up being a huge hit. Perez, he fought for that hit."
Said catcher Nick Hundley: "You give [Perez] credit, because he did a good job. He shot one down the right-field line, kept it fair."
Weiss opened the inning with left-hander Jake McGee in relief of starter Jon Gray, who threw six innings of two-run ball while striking out 10. McGee retired the first batter, but allowed a double to pinch-hitter Orlando Arcia.
McGee was replaced by another lefty in Boone Logan. One pitch after just missing a would-be go-ahead homer foul, Villar plated Arcia with another double. Logan then struck out Scooter Gennett to bring up Braun.
In Estevez, the Rockies had a righty-on-righty matchup against Perez, although the Brewers infielder has a higher average and on-base percentage against right-handers this season. Entering the day, right-handers were batting .163 with a .564 OPS against Boone compared to .280 and .827 against Estevez.
Reliever Matt Carasiti allowed an insurance run in the eighth, leaving the bullpen with four runs conceded in two innings on Tuesday. The Rockies' bullpen ERA jumped to 4.86 on the season, which ranks third-worst in the Majors.
"We've got some young, talented guys in the bullpen that are learning on the job," Weiss said. "Sometimes you go through these types of things. It's always frustrating when you're winning late and don't put the game away, no doubt."