PITTSBURGH -- Josh Harrison tripled in the bottom of the ninth inning and scored on the play after second baseman Scooter Gennett's throwing error as the Pittsburgh Pirates rallied to beat the Milwaukee Brewers 3-2 on Tuesday night.

Harrison drove the second pitch by reliever Tyler Thornburg (3-4) off the top of the wall in right-center field as center fielder Kirk Nieuwhenhuis failed to make a leaping catch, then kept on going as Gennett's throw sailed wide of third.

Pirates closer Mark Melancon (1-1) got the win but blew a save opportunity for the second time in as many games -- he’s 27 of 30 -- when, with Milwaukee down to its final strike in the top of the inning, Hernan Perez singled to make it 2-all in the ninth. Ryan Braun walked to start the inning and Jonathan Lucroy singled.

Well before that, another Perez liner -- this one off the head of rookie right-hander Jameson Taillon in the second -- gave the Pirates a big scare but wasn't enough to drive him from the game.

Taillon needed only 65 pitches to check the Brewers on one run and five hits in six innings, striking out three and walking none, and relievers Neftali Feliz and Tony Watson pitched a scoreless inning each.

Brewers starter Junior Guerra also pitched effectively, giving up two runs and three hits in six innings.

The Pirates missed on a chance to build on their 2-1 lead when Jordy Mercer led off the seventh with a triple, but reliever Corey Knebel put down the threat by retiring the next three batters, including strikeouts of John Jaso and Gregory Polanco.

Taillon gave the Pirates an excellent start -- and quite a scare.

With one out in the second, Taillon threw up his glove to try to deflect a Perez line drive, but it struck him in the back of the left side of his head. Taillon immediately fell to the mound as the ball ricocheted into left field, but he regained his feet after several minutes and stayed in the game.

Taillon, one of the Pirates' top pitching prospects, was making his sixth major league start and his first since going on the disabled list because of shoulder fatigue after a June 29 start in Seattle.

The Pirates already led 2-0 when Taillon was momentarily shaken up. Gregory Polanco, back in the lineup for the first time since injuring a hamstring on July 8, walked with one out in the first ahead of Andrew McCutchen's single off Junior Guerra. McCutchen was coming off an 0-for-8 effort Sunday in the Pirates' 2-1, 18-inning win at Washington.

Starling Marte walked to load the bases, setting up David Freese's run-scoring single to right. Francisco Cervelli, making his first start since breaking a hamate bone in his left wrist on June 10 in St. Louis, then lifted a sacrifice fly to right.

The Brewers, who scored only two runs in the final two games of their weekend series in Cincinnati, got a run in the fourth on Chris Carter's leadoff double and two groundouts.

NOTES: The Pirates activated C Francisco Cervelli and RHP Jameson Taillon from Triple-A Indianapolis, optioned RHP Chad Kuhl to Indianapolis and designated C Eric Kratz for assignment. Kratz caught all 18 innings Sunday in Washington, his 15th start since Cervelli went on the disabled list in mid-June. Kuhl pitched six shutout innings in that game, allowing only one hit. ... The Brewers finish out the season by playing 30 of 72 games against the Pirates and the Chicago Cubs, including nine of 13 starting Tuesday night. ... RHP Junior Guerra, the Brewers' top starter during the first half of the season, pitched on eight days' rest Tuesday in Pittsburgh. He began the game with 82 1/3 innings pitched, only five fewer than his 2015 season total.