OAKLAND, Calif. -- Drew Pomeranz approached his fill-in start the same way he has every outing in relief this season. Maybe that's why he had so much more success than he's used to as a starter.
Pomeranz pitched five scoreless innings for his second win in his past 20 starts and the Oakland Athletics salvaged a split of a doubleheader by beating the Seattle Mariners 2-0 in the nightcap Wednesday.
"It felt a little weird at first," Pomeranz said. "I was trying to take the same mentality I've had all year. I've had some success doing that, staying in the stretch, keeping things as simple as I can out there. Just tried to treat it like I was coming into a game."
The Mariners overcame a shaky start from ace Felix Hernandez to win the opener 6-4 on Justin Smoak's two-out single in the 10th inning. Despite the loss in the nightcap, Seattle heads home satisfied following a 7-2 road trip that also included stops in New York and Houston.
"To come out of this series 7-2 is just an unbelievable trip in my opinion," manager Lloyd McClendon said. "Just phenomenal. I was very proud of the team and how they played. We put ourselves in a pretty good position."
Pomeranz (2-1) was sharp in his first major league start since last July, allowing two hits and no walks in five innings with five strikeouts as he mixed in his change-up for the first time all season.
Pomeranz won just one of his final 19 starts with Colorado, leading to an offseason trade to the A's where he has pitched well in relief. But he stepped when the A's needed another starter for the doubleheader and got the win.
"I couldn't have expected any more than that," manager Bob Melvin aid. "Pretty fantastic for a guy who hasn't started a game for us in spring or this season."
The A's took the lead in the third. Gentry ran on the pitch from first base on a full count with two outs when Lowrie's popup fell between left fielder Cole Gillespie and shortstop Brad Miller for a hit.
Cespedes added to the lead in the fourth with a solo homer off Erasmo Ramirez (1-4), who was called up from Triple-A Tacoma earlier in the day to make the start. Ramirez allowed two runs in six innings.
Dan Otero, who allowed the go-ahead hit in the 10th inning of the opener, pitched three scoreless innings of relief and Jim Johnson finished the three-hitter for his second save and first since losing the closer's job a month ago.
"That's what he's used to doing -- 1-2-3 today," Melvin said. "That was huge."
This was just the second traditional doubleheader in Oakland in the past 16 years, with the other in 2011. The makeup game was necessary because a game was postponed April 4 when the field was unplayable after there was no tarp on it overnight.
Hernandez failed to strike out a batter for the first time Aug. 19, 2008, against the Chicago White Sox, ending a streak of 179 straight starts with at least one strikeout. He allowed four runs -- three earned -- and matched his career worst against Oakland by giving up 11 hits in 6 1/3 innings.
"No strikeouts, not a good breaking ball, not a good change-up," Hernandez said. "That's what happens when you don't have good stuff."
Brandon Moss hit an RBI triple that capped a three-run seventh against Hernandez, but the A's could not hold a late lead as Robinson Cano tied the game with an RBI single off Luke Gregerson in the eighth.
Smoak gave the Mariners the lead when he hit a chopper off the glove of leaping first baseman Daric Barton for an RBI single off Otero in the 10th after Ryan Cook (0-1) left the game with a strained right forearm. Cook will have an MRI on Thursday but does not believe the injury is serious.
Oakland center fielder Coco Crisp strained his neck in the opener crashing into the wall to make a leaping catch. He is expected to miss a few days.
Corey Hart and Mike Zunino hit solo homers for the Mariners in the opener. ... Hisashi Iwakuma (1-0) takes the mound for the Mariners on Thursday when they open a four-game home series against Kansas City. ... Oakland begins a three-game series at home against Washington on Friday.