SAN DIEGO (AP) -- Manager Clint Hurdle doesn't care whether people call Francisco Liriano the Pittsburgh Pirates' ace or No. 1 or whatever.
''I'm not big on labels. I just like to pencil his name in every fifth day,'' Hurdle said after Liriano struck out a season-high 13 to lead Pittsburgh to a 3-1 victory against the San Diego Padres on Monday night.
''I'd never take it for granted and I hope nobody else does when you watch a man go out there and pitch like he does,'' Hurdle said. ''I hope there's some appreciation. He continues to just be masterful.''
Pedro Alvarez hit his NL-leading 31st home run and the Pirates, who had lost seven of nine coming in, maintained a one-game lead in the NL Central over St. Louis.
The Padres struck out 17 times overall Monday night, giving them 59 in their last five games. They've lost nine of 13.
Liriano (14-5) tied his career-high with his 14th victory. He helped give some relief to the Pirates' bullpen, which was taxed when three of the previous six games went extra innings.
Coming off a four-hit victory at St. Louis in his last start, Liriano held San Diego to four hits in seven innings while walking two.
Liriano's previous season high was 11 strikeouts on June 1 against Cincinnati. His career high is 15.
Liriano struck out five of the first seven batters and eight of the first 11.
''I was very confident in my fastball,'' he said. ''I threw it in and out for strikes. Breaking balls were easy for me to throw. I got very confident in my pitches. Instead of trying to do too much, I just hit my spot and let whatever happen.''
The Padres loaded the bases with two outs in the fourth before Liriano got Ronny Cedeno to hit into a force.
The Padres had runners in scoring position only two other times against Liriano. Cedeno hit a leadoff single in the third and advanced on a balk before Liriano struck out the side. Chris Denorfia doubled to left with one out in the fifth and advanced to third on Will Venable's groundout before Liriano struck out rookie Jedd Gyorko.
''The situation tonight that shows his growth, and one of the reasons he's having the year he's having is his ability to continue to pitch through traffic, to pitch out of the stretch, with runners in scoring position, runners on base,'' Hurdle said. ''He was in command and never panicked when he got some people on base. He made pitches he needed to get out of it.''
In his last four starts after a Bucs' loss, including Monday night, Liriano has pitched 30 innings and allowed only two earned runs.
''He has an explosive fastball,'' Denorfia said. ''He works every part of the zone. He can duplicate his off-speed pitches. It was the first time seeing him this year. There was definitely some adjusting we needed to do. Unfortunately, we couldn't get it done.''
Mark Melancon pitched the ninth for his eighth save in 10 chances. He allowed Nick Hundley's RBI double with two outs.
Alvarez, who had been tied for the NL lead with Arizona's Paul Goldschmidt, homered on an 0-1 pitch from Andrew Cashner with two outs in the sixth to give the Pirates a 3-0 lead. It landed about six rows behind the Jack Daniel's Old No. 7 party deck that sits atop the right-field wall.
The Pirates scored two runs in the fourth on two singles and an error by right fielder Denorfia. With Andrew McCutchen aboard on a leadoff single, Alvarez grounded a single to right field, which rolled under the glove of a charging Denorfia and went all the way to the fence, allowing both runners to score.
''I just missed it,'' Denorfia said. ''There really is no excuse for it. It's one of those plays that cost us the game.''
Cashner (8-8) lost his third straight start. He allowed three runs, one earned, on five hits in seven innings, struck out three and walked two.
NOTES: Padres CF Cameron Maybin returned to San Diego to have his injured knee re-examined by club doctors. Maybin has been on a rehab assignment with Triple-A Tucson before the club shut him down. He probably is done for the season. ... Pirates RHP A.J. Burnett (5-8, 3.18) is scheduled to start against the Padres on Tuesday night. He's 1-5 with a 4.93 ERA in seven career starts against the Padres, with the one victory being a no-hitter on May 12, 2001, while with the Marlins. Burnett walked nine that night. ... In his last start on Aug. 15, Burnett allowed five runs in 4 1-3 innings and got a no-decision at St. Louis. Burnett has allowed 11 runs in his last two starts after throwing a complete-game victory Aug. 4 against the Rockies. ... The Padres will counter with Tyson Ross (3-5, 2.62) Tuesday night. ... LHP Wandy Rodriguez threw a bullpen session Monday. Rodriguez, who has been on the disabled list since June 11, retroactive to June 6, with tightness in his left forearm, said he still could ''feel something'' in his arm during the session. There is no timetable for his return. ... RHP Jason Grilli was scheduled to start throwing from a 120 feet Monday, manager Clint Hurdle said. Grilli has been on the DL since July 23 with a right forearm strain. ... RHP Ryan Reid was recalled Monday from Triple-A Indianapolis. This is Reid's second stint with the Pirates.