PITTSBURGH - Sellout crowds, a pennant race, a five-game winning streak.
Baseball is fun in Pittsburgh again, enough so that Jeff Karstens said he's pitching as if he's a kid again.
Karstens pitched seven strong innings, Pedro Alvarez homered and the surging Pittsburgh Pirates beat the Miami Marlins 3-0 on Sunday for their fifth consecutive win.
Karstens (3-2) allowed five hits, struck out three and walked two. He has allowed one run in three home starts this season for a 0.43 ERA.
"I was kind of playing whiffle ball out there," Karstens said. "I just think to when I was a little kid, honestly, to make them take unorthodox swings - really bad swings. That's all I'm trying to do. I'm not trying to blow fastballs by people; I'm just trying to keep people off-balance, and when they do hit the ball hard, hopefully it's right at us."
Pittsburgh completed its fourth sweep of the season - all at home - while matching its longest winning streak since Sept. 17-22, 2010.
The Pirates (54-40) remained a half-game behind NL Central-leading Cincinnati.
Miami has lost five straight, scoring a total of seven runs during the slide.
Alvarez's fourth homer in his past six games and No. 21 for the season came off Anibal Sanchez after Casey McGehee led off the seventh with a double, making it 3-0.
"I tried to throw something different to get an out, a groundball or something like that," Sanchez said. "But that's what's happening right now."
Jared Hughes worked a perfect eighth and Joel Hanrahan retired the Marlins in order for his 28th save in 31 opportunities. Alvarez went 2 for 3 and Andrew McCutchen had two more hits to improve his major league-leading batting average to .372.
The Pirates have won 21 of their past 25 games at PNC Park to run their home record to a majors-best 32-14.
Karstens and Sanchez cruised through the middle part of the game. Sanchez retired 12 straight from the end of the second until a two-out single by McCutchen in the sixth, and Karstens sent down 15 of the next 16 he faced after a rocky first inning.