Pirates 2, Reds 1: Andrew McCutchen belted a walkoff homer to snap a tie in the ninth inning as host Pittsburgh dealt Cincinnati a blow to its bid for home-field advantage throughout the playoffs.

After Jonathan Broxton (3-2) retired his first batter, McCutchen snapped an 0-for-16 drought by blasting an offering deep to right-center field to send PNC Park into a frenzy. The homer was McCutchen's 31st of the season.

Alex Presley ended a scoreless tie with an RBI double in the seventh inning for the Pirates (77-81), who need to win their final four games to prevent their 20th consecutive losing season.

Scott Rolen had an RBI single in the eighth inning for the Reds, who fell one game behind Washington. The Nationals posted a 6-4 triumph over St. Louis on Saturday.

Joel Hanrahan (5-1) overcame a pair of walks to work a scoreless inning to pick up the victory.

GAME NOTEBOOK: McCutchen went 1-for-5 to see his average dip to .329. San Francisco's Buster Posey, who leads the National League with a .337 average in Melky Cabrera's absence, went 2-for-2 against San Diego later on Saturday. ... Cincinnati's Mike Leake pitched six solid innings, but settled for a no-decision to remain winless (0-3) in six career starts at PNC Park. ... Pittsburgh posted its 17th sellout of the season, matching its 2011 total.