Manager Walt Weiss emerged from the dugout and challenged the call.
"It was one of those that was probably too close to call at real speed," Weiss said. "I wasn't sure which way it was going to go, but I felt we had a shot to win that one. It was really close -- even looking at the replay it was tough to tell. It was a tough call, and it went our way."
The four umpires, led by crew chief Mike Winters, stepped off to review the play, and two minutes and 14 seconds later returned to the field with a safe call for Blackmon, giving the right fielder his 10th hit in his last 11 trips to the plate.
Though the overturned call helped Blackmon's hot start to the season, it didn't have an impact on the game, as the next batter, Michael Cuddyer, hit a double-play grounder to short, and Carlos Gonzalez grounded out to end the inning with the score 0-0.
"The first batter in the first inning -- we can't predict the future and say it's not a big play," Weiss said. "You get four outs in this league and you usually score."
Because Weiss won the challenge, he retained the right to make another challenge later in the game. If he had lost the challenge, he would only be able to suggest the umpires review a call for the duration of the game.
"We get feedback pretty quickly from upstairs," Weiss said. "The one that's a tough one is the one that's inconclusive. You have to try and determine if it's worth challenging that one. If the replay shows that the call was missed, I'm going to challenge that 100 percent of the time, regardless of how big I think the play is or anything else."
Weiss has made one previous challenge, trying to overturn a stolen base from the Marlins in the eighth inning Thursday. The Rockies led, 5-4, going into the inning, and the game was tied when the base was stolen. Weiss lost that challenge, and the Marlins scored three more times in the frame, giving them their 8-5 margin of victory.