Alvarez drove in all of Pittsburgh's runs with a solo homer, bases-loaded double and a single on Thursday for a 5-3 victory over the Cincinnati Reds and a split of their high-profile NL Central series.
The Pirates remain a half-game behind second-place Cincinnati after the four-game set, keeping them virtually shoulder-to-shoulder as they chase the torrid St. Louis Cardinals.
After blowing a one-run lead in the ninth and losing 2-1 in 13 innings on Wednesday night, Pittsburgh salvaged a game behind Alvarez and a bullpen running on fumes.
"We needed a big day from a number of people today and Pedro was one of them," manager Clint Hurdle said. "There was no bigger swing than with the bases loaded, left-on-left. Beautiful."
Alvarez had an RBI single and his 16th homer off Homer Bailey, who couldn't follow his no-hitter against Pittsburgh last season with a win. After Alfredo Simon (5-3) loaded the bases in the seventh, Alvarez doubled off left-hander Tony Cingrani to snap a 2-all tie.
The five RBI were a season high for a Pirate and one shy of Alvarez's career high. The third baseman has been Pittsburgh's top run producer in June, leading the team with 48 RBI overall.
It's quite a change. Alvarez hit .180 in April and .225 in May before finding his form. He has six homers in June, second most in the NL.
"I just think it's repetition and getting the opportunity to go out and try to gain as much experience as I can from every day out there," Alvarez said.
Bryan Morris (4-2) contributed to the go-ahead rally with his first career single. He also pitched two innings, allowing one run. Left-hander Tony Watson pitched the final two innings for his second save in three chances.
The Pirates lead the season series 6-4, holding their own early in the season despite a rotation that has been sapped by injuries and a lineup that strikes out a lot and wastes chances. Under the circumstances, the way the series ended was satisfying.
"We don't expect anything less," Morris said. "It's good to not lose any ground. Definitely would have loved to have three out of four in the series, but we're not complaining about the split, especially after the hard game last night."
The teams combined for seven homers in the series, all solo shots. Cincinnati hit four in a 4-1 win that opened it.
Brandon Cumpton made his second major-league start for Pittsburgh, giving up two runs -- one earned -- in five innings.
Bailey faced the Pirates for the first time since his no-hitter at PNC Park last September and left after six innings with the score tied at 2. He gave up six hits, throwing 113 pitches. Bailey is 8-2 career against Pittsburgh.
"They've definitely made strides over the past couple of years, but it's early," Bailey said. "They have a good club but the past couple of years, they've fallen into the pattern of fading, so we'll see. It's a long season."
Another batter got hit, extending a prominent theme to the Ohio River rivals' series this season. At least one batter has been plunked in each of the 10 games, with 19 hit overall. Pirate pitchers have hit 10, Reds pitchers 9, leaving some simmering unhappiness on both sides.
- The official scorer changed a call from Wednesday night's game. Russell Martin's grounder off Bronson Arroyo's glove was originally ruled an error, leaving the Pirates' lone run unearned. It was changed to a hit.
- The Pirates added to their depleted bullpen by calling up right-hander Duke Welker from Triple-A and optioning OF Alex Presley.
- A day after actor James Gandolfini died, Reds 3B and New Jersey native Todd Frazier replaced his Frank Sinatra at-bat music with the theme from The Sopranos.
- Pittsburgh struck out 8, 17, 10 and 12 times in the four games.
- The Pirates head to the West Coast to play three against the Angels and two in Seattle. The Reds have an eight-game trip to Arizona, Oakland and Texas.