Alvarez hit a grand slam in Pittsburgh's nine-run first and a solo drive in the second for his first career multihomer game, helping the Pirates beat the Milwaukee Brewers 11-9 on Tuesday night.
Fellow rookie Neil Walker had a career-high five hits for the Pirates, who got 3 2/3 scoreless innings from four relievers after the Brewers got within one.
"It was like running in a 100-meter dash and then running in a marathon," said Walker, who had two hits, scored a run and drove in another, just in the first inning. "That first inning was awesome; certainly nobody wanted to make the last out ... I wish we could have added on about six more."
Pittsburgh, the National League's worst offensive team at the All-Star break, has scored at least nine runs in three of their last four games.
Sloppy Milwaukee committed three errors over a six-pitch span in Pittsburgh's big first and the nine runs allowed in the opening frame set a Brewers record.
Alvarez hit a 2-2 pitch from Dave Bush (4-8) over the wall in right for his fourth homer and Pittsburgh's second slam of the season. Third baseman Casey McGehee's error allowed another run to score, and Jose Tabata, Delwyn Young and Walker hit consecutive RBI doubles.
"Everything went wrong that inning," Bush said. "Pretty much everything that I threw up there was getting hit.
"It's too bad because we scored a lot of runs afterwards."
It was the first time Pittsburgh scored nine or more runs in the first inning at home since it got nine against the Chicago Colts on Aug. 8, 1893, according to research by the Elias Sports Bureau, and just the third time in franchise history.
Milwaukee, which beat Pittsburgh 20-0 at PNC Park on April 22, responded with three in the second and four in the third. The big blow was Edmonds' three-run drive off rookie Brad Lincoln in the third, his 13th in 184 at-bats at the Pirates' home.
"That game never should have gotten to the point it did," Lincoln said. "I take that all up on my shoulders to, when you get a team down like that, to hold them, keep them down. I just didn't do that tonight and I guess you could say I got comfortable out there. That's not the way to go about things and it hurt me tonight."
Javier Lopez got two outs and All-Star Evan Meek, Joel Hanrahan and Octavio Dotel each pitched a scoreless inning after Braun's 15th homer. Dotel allowed Edmonds' double in the ninth but struck out the side for his 20th save in 25 opportunities.
"You have to give our guys credit, you know, 9-0, and made it a ballgame," Brewers manager Ken Macha said. "Things were getting interesting. ... We just dug too deep of a hole in the first inning."
D.J. Carrasco (2-2) got the win with 2 2/3 scoreless innings in relief of Lincoln. He allowed one hit, walked one and struck out five.
Bush was charged with 10 runs, five earned, and nine hits in four innings.
Alvarez, the 2008 No. 2 overall draft pick who arrived in Pittsburgh last month to great fanfare, is hitting .315 with all five of his homers in July after his average was at .114 on June 27.
"I feel a lot more comfortable than when I first started," Alvarez said. "That's what I try to do, just get in a groove and get more and more comfortable."
- The Brewers had twice allowed eight runs in the first inning of a game, most recently August 3, 1991, against Texas.
- The previous time the Pirates had as many as nine runs in the first inning of a game was June 8, 1989, when they scored 10 at Philadelphia. They most recently had nine in any inning on May 17, 2009, versus Colorado with 10 in the seventh.
- The last Pirates rookie to have five hits in game was John Wehner on July 23, 1991.
- Pirates manager John Russell was ejected by first base umpire D.J. Reyburn for arguing a call during the seventh inning.