ARLINGTON, Texas -- Francisco Liriano pitched six innings for his career-high 16th victory, Andrew McCutchen had three RBI singles and the Pittsburgh Pirates held on to beat the slumping Texas Rangers 5-4 on Tuesday night.
A night after victory No. 82 ensured the Pirates first winning season since 1992, the NL wild-card leaders added a series-clinching victory.
Pittsburgh scored three runs with four consecutive two-out hits in the fifth off rookie left-hander Martin Perez (9-4), who had won his previous six starts since the beginning of August.
The Rangers, who still need another victory for their fifth consecutive winning season, will lose their fourth series in a row no matter what happens in Wednesday's finale. Texas has lost seven of its last nine games, but remained two games back in the AL West with Oakland's loss to Minnesota.
Liriano (16-7) struck out five while allowing one run to become the first Pirates left-hander since John Smiley and Zane Smith in 1991 to win more than 15 games. Liriano has received a decision in each of his 23 starts since signing as a free agent in February, the most for the Pirates since Larry French got a decision in each of his first 24 starts in 1930.
Mark Melancon worked a shaky ninth for his 13th save in 15 chances. After striking out the first two batters, Melancon gave up four consecutive two-out singles -- Ian Kinsler and Alex Rios drove in runs -- before Adrian Beltre struck out to end the game.
Pittsburgh remained a game behind NL Central-leading St. Louis, which beat Milwaukee 4-2.
In the Pittsburgh fifth, Jordy Mercer doubled and went to third on left fielder Craig Gentry's error before scoring on McCutchen's second hit. Marlon Byrd then singled before Gaby Sanchez had an RBI double. Byrd scored on a wild pitch.
The 22-year-old Perez is the only Texas rookie ever to win six consecutive starts, and it was the most for any Rangers pitcher since Kenny Rogers won eight in a row in 2005.
Texas got a run off Jason Grilli in the eighth, when Rios doubled with two out and scored on a single by Beltre. Tony Watson took over and allowed a double to A.J. Pierzynski before striking out Jeff Baker to end the inning.
Pittsburgh went up 1-0 in the third when it appeared that Tony Sanchez stepped on the foot of catcher A.J. Pierzynski and never actually touched the plate.
Sanchez had a leadoff double, went to third on Mercer's single and scored on McCutchen's infield single that ricocheted off Perez, whose throw home was late.
Texas rookie Joey Butler drew a leadoff walk in the fifth and scored on Kinsler's double to center, a ball that went off the glove of McCutchen as he tried to make a sliding backhanded catch.
NOTES: The Pirates have 38 road wins, their most since that same amount in 1992. ... Texas also lost four consecutive series in June. ... The Rangers had been safe on 19 consecutive stolen bases until Elvis Andrus was caught in the third inning. ... Kinsler's double snapped a 15-inning drought for the Rangers without a run or an extra-base hit. ... There was a disputed double play by Pittsburgh in the fourth. Pierzynski hit a grounder that 1B Sanchez backhanded while apparently sliding his foot across the base before throwing to second base to get Beltre. Pierzynski argued with first-base umpire Chad Fairchild before manager Ron Washington and Beltre joined the discussion.