SAN DIEGO (AP) -- At the end of the longest nine-inning game in San Diego Padres history, Pirates manager Clint Hurdle summed it up best Monday night.
''It's time to go home,'' he said.
Jordy Mercer homered and matched a career high with four of Pittsburgh's 16 hits in a 10-3 romp over the Padres.
The Pirates are enjoying their West Coast swing so far. After taking three of four at Dodger Stadium, they headed south and won again in a game that took 4 hours, 4 minutes.
''It was a long one, that's for sure,'' Mercer said. ''But it is always good when you score a lot of runs.''
Charlie Morton (2-7) tied a career best with nine strikeouts in five innings. He allowed two runs and three hits in winning for the first time in five road starts this year.
Three relievers finished the five-hitter after Morton's curveball baffled the Padres.
''He was still dealing with baserunners,'' Hurdle said. ''But he was able to compete and get outs when he needed to. He gave us five solid innings.''
Mercer scored four times from the No. 8 spot in the batting order and went 4 for 5 to raise his average 20 points to .219. He entered with one home run and seven RBIs in 146 at-bats.
''The people believe in me here,'' Mercer said. ''Having that support, having that confidence every time, it's nice.''
Hurdle talked about how dangerous this Pirates lineup can be.
''I think when we all get hot there's no telling what we can do,'' Mercer said. ''The sky's the limit for us because we can hit the ball out of the ballpark, we can run, we can do all sorts of stuff. It's just a matter of us all clicking together.''
Tim Stauffer (2-2) lasted only 2 2-3 innings, his second consecutive disappointing start since being inserted into the rotation because of elbow injuries to Andrew Cashner and Robbie Erlin.
''The first two innings were pretty good, then he seemed to lose the feeling for his pitches,'' San Diego manager Bud Black said.
The Padres threw 249 pitches, the most ever by their staff in a nine-inning game.
''It was just unfortunate it unraveled the way it did,'' Stauffer said.
The Pirates broke open the game with three runs each in the seventh and eighth. The big blow was Walker's two-run double in the seventh, propelling Pittsburgh to its sixth win in the last nine road games.
Four times in the previous six innings the Pirates loaded the bases but scored only one run. They stranded a season-high 16 runners.
The teams combined for 12 walks and six hit batters.
Through the first four innings, Morton didn't allow a run or hit - although the Padres reached on an error, two walks and two hit batters.
But in the fifth, Everth Cabrera's double drove in Alexi Amarista after he opened the inning with a single. Seth Smith drove in Cabrera with a single, trimming the Pirates' lead to 3-2, but pinch-hitter Tommy Medica struck out with the bases loaded.
Pittsburgh had extended its advantage to 3-0 on Mercer's RBI single in the fourth. Starling Marte scored after he was hit by a pitch from reliever Alex Torres.
Mercer snapped a scoreless tie with a home run to start the third inning, a 414-foot shot into the second deck beyond the left-field fence. Ike Davis' sacrifice fly scored Harrison for a 2-0 lead.
NOTES: Cashner threw a four-inning simulated game and didn't report any discomfort. Cashner, on the DL since mid-May with a sore right elbow, could start this weekend. ''That was a good step forward,'' Black said. Cashner said he's adjusted the grip on his slider to take pressure off his elbow. ... Erlin hasn't been cleared to resume throwing. He's on the DL with a sore left elbow. ... Pirates RHP Stolmy Pimentel (right shoulder inflammation) made a rehab start at Class-A Bradenton, throwing two scoreless innings. ... Harrison has batted leadoff 15 straight times, the longest stretch by a Pirates player this season. ... RHP Gerrit Cole (5-3, 3.80 ERA) faces Padres RHP Jesse Hahn on Tuesday. It will be Hahn's major league debut after appearing in 10 games with Double-A San Antonio, where he was 2-1 with a 2.20 ERA.