MIAMI -- On a night in which the Pittsburgh Pirates got outstanding pitching from Gerrit Cole, Tony Watson and Mark Melancon, first baseman Pedro Alvarez made the biggest impression of all.

Alvarez's solo home run turned out to be the difference as the Pirates defeated the Miami Marlins 2-1 on Thursday night at Marlins Park.

"Pedro has as much raw power as anybody in the game -- except for maybe the guy over there (Marlins right fielder Giancarlo Stanton)," Pirates manager Clint Hurdle said. "Pedro's run-producing ability has carried us in the past."

The lefty-hitting Alvarez is hitting .354 with six homers in his past 18 games. He is trying to show Hurdle he can hit lefty pitchers, even though he has been given just 50 at-bats against southpaws this season.

Hurdle is hoping Alvarez can get hot again and that his power combines with the type of starting pitching they got on Thursday from right-hander Cole, who won his 15th game of the season.

Cole, an All-Star who had lost his past three decisions, improved to 15-7, allowing five hits, no walks and one run in 7 1/3 innings. It was his first win since July 26.

"He's one of the better pitchers in the National League," Marlins manager Dan Jennings said. "His stuff is quality."

Cole tied the St. Louis Cardinals' Michael Wacha for second place in the National League wins race. Madison Bumgarner of the San Francisco Giants and Jake Arrieta of the Chicago Cubs lead the league with 16 wins.

Alvarez hit his homer over the 418-foot sign in center field. It was his 21st homer of the season but just his third off a left-handed pitcher.

The lefty on this occasion was Marlins rookie Justin Nicolino (2-2), who allowed six hits, four walks and two runs in six innings.

"I thought 'Nico' battled," Jennings said, "even though he didn't have his best command."

Pittsburgh (77-49) opened the scoring in the second inning when catcher Francisco Cervelli led off with a triple to the warning track, his blast glancing off the glove of center fielder Marcell Ozuna. Cervelli scored on a sacrifice fly by second baseman Neil Walker.

Nicolino got out of a bases-loaded, two-out jam in the third by getting Cervelli to ground out to second. Cervelli, though, apparently didn't like one of the strikes called during his at-bat.

In the next inning, while playing defense, Cervelli objected when a similar pitch to Marlins catcher Jeff Mathis was called a ball. Cervelli was ejected from the game for arguing balls and strikes.

"(Plate umpire Alan Porter) shared his comments and took Cervelli in the wrong direction," Hurdle said. "It was a quick hook -- that's all I have to say."

Cervelli said Porter got on him for holding onto the ball too long in his attempt to frame pitches.

"I didn't like the tone of voice he used with me," Cervelli said in Spanish. "In no moment did I disrespect him or say a bad word or anything bad. I simply held the ball too long. Next time, I will try to find a different way so I don't get ejected."

Alvarez's fourth-inning homer gave the Pirates a 2-0 lead, but Miami (51-77) battled back with a run in the seventh. Third baseman Martin Prado led off with a single, raced to third on Ozuna's one-one single and scored on left fielder Derek Dietrich's sacrifice fly.

The Pirates got good relief pitching in the eighth from left-hander Watson, who inherited a runner on second and got two outs to escape the jam. As part of Watson's work, he struck out second baseman Dee Gordon, who started the day as the NL batting leader.

Melancon pitched a scoreless ninth and earned his career-high 41st save of the season, getting first baseman Justin Bour to bounce into a key double play.

Entering the night, Melancon was tied for the major league lead in saves.

"We've been smart with his ups -- he rarely gets up and doesn't get in," Hurdle said of Melancon. "He conditions extremely well. He has put an exclamation point on 41 games for us."

NOTES: Manager Clint Hurdle said the Pirates are still weighing whether to promote highly rated RHP Tyler Glasnow to the majors in September, according to the Pittsburgh Tribune-Review. ... Pirates RHP A.J. Burnett, who hasn't pitched since July 30 due to an elbow injury, expects to make at least three major league starts before the playoffs. ... Pirates C Francisco Cervelli (two banged-up feet) was back in the starting lineup. Hurdle said Cervelli could have played Wednesday had he been needed. ... Marlins RHP Andre Rienzo (left knee laceration) was activated from the disabled list. RHP Scott McGough was optioned to Triple-A New Orleans. ... Miami LF Christian Yelich (right ankle, right knee) did not start and is day-to-day. ... Marlins RF Giancarlo Stanton (fractured left wrist) is set to take batting practice at Class A Jupiter on Monday or Tuesday. ... Marlins RHP Jarred Cosart (vertigo) was set to throw his final rehab game Thursday night at Jupiter.