The Pittsburgh Pirates found out that the Oakland Athletics can have nights where they play better than their mere 12 wins.

Not well enough to beat the Pirates on Monday, though, as Pittsburgh claimed the opener of a three-game set 5-4 for its sixth straight win. However, in what was a back-and-forth game, the Athletics showed that they can compete with the top team in the National League Central.

Oakland will have a chance to prove itself once again on Tuesday when it continues its series with the host Pirates.

The A's set the tone early on Monday, taking a three-run lead in the third inning. The Pirates surged back to move ahead by a run, only to have Oakland tie it in the top of the eighth. Then Andrew McCutchen squashed the Athletics' hopes of winning with his go-ahead sacrifice fly in the home half of the frame, driving in what ended up being the decisive run.

It could have been seen as a rousing win for the Pirates, but their most respected veteran urged caution.

"Relax. It's June," McCutchen told ATT Sportsnet.

Oakland starter JP Sears held the Pirates hitless through the first four innings, and the A's were resilient, but they still lost their fifth game in a row and took their 15th straight road loss, matching the franchise's Oakland-era record.

On Tuesday, A's right-hander James Kaprielian (0-6, 8.12 ERA) is scheduled to start opposite Pirates right-hander Mitch Keller (7-1, 3.25).

Kaprielian has split time this season between Oakland and Triple-A Las Vegas. He is the first A's pitcher to start a season 0-6 since Mike Mohler lost his first eight decisions in 1997.

Kaprielian has the dubious distinction of pitching no more than seven innings in all 54 of his career starts.

Most recently, he gave up three runs and five hits in 4 2/3 innings on Wednesday in a loss against the Atlanta Braves. He retired 13 of the first 14 batters he faced.

"I felt like we were doing a good job of mixing the fastball, slider and changeup," Kaprielian said. "Stuff was on (Wednesday). Arm felt fluid. I think things are moving in the right direction where that deception is there."

Kaprielian said his slider has returned to form after he had offseason shoulder surgery.

"Just being on time," said Kaprielian, who has never faced Pittsburgh. "When I'm in the right position with my body and my mechanics have that right rhythm, my arm's in the right spot and I'm not really thinking about anything. I've got my grip and I'm going for it, trusting my stuff."

Keller, who has never faced the A's, has won four decisions in a row and has notched at least eight strikeouts in seven straight outings while establishing himself as the Pirates' ace.

On Wednesday, Keller had a bit of an off game by his standards against San Francisco, as he gave up four runs and 10 hits in six innings. However, he still picked up a win as Pittsburgh topped the Giants 9-4.

"I was definitely coming in trying to throw zeros and give us a chance to win," Keller said. "Our offense kind of took care of that. I didn't really do too much -- just throw strikes and not let them score eight."