PITTSBURGH -- Apparently the only thing that can stop the Pirates’ starting pitching right now is a hard-hit comebacker.

Right-hander Jordan Lyles continued an excellent run by Pittsburgh’s rotation on Friday night, striking out six over six scoreless innings, before exiting the Pirates’ 4-1 win over the Giants at PNC Park with a right hand contusion. Lyles’ throwing hand was clipped by Joe Panik’s low line drive in the sixth inning, which Erik Gonzalez turned into a double play.

Lyles felt like he could have worked another inning, but his fingers started swelling up after the sixth. After undergoing tests, Lyles declared himself “good to go” for his next scheduled start on Wednesday.

The way he’s been pitching, that’s good news for the Pirates and bad news for the D-backs.

“He’s been fun to watch,” manager Clint Hurdle said.

Lyles, signed for only $2.05 million this offseason, lowered his ERA to a Major League-best 0.53 after three starts. Overall, Pittsburgh’s starters have put together a 1.97 ERA -- the driving force behind the Pirates’ early ascent to first place in the National League Central despite a number of key injuries.

“We’ve talked about our starting pitching since the end of last season. I think every man out there will tell you the part we’ve got in a really good spot is our starting pitching,” Hurdle said before Friday’s game. “It’s no secret. They’re all well aware of it. You want to get the rest of the league to recognize it, and you do that by pitching well on the mound.”

How has Lyles pitched so well? It starts with his pitch mix, which the Pirates identified over the offseason as an indicator of his untapped potential. Lyles once again relied on his fastball and curveball while mixing in changeups to keep San Francisco’s lineup off balance.

Lyles is also clearly comfortable pitching for Pittsburgh. How did that happen so quickly?

“Some decent outings,” he said, grinning. “What led to that is, first and foremost, [Francisco] Cervelli behind the plate. It’s very comforting to stand on the mound and trust what fingers he’s putting down, what game plan we’re trying to attack. Secondly, it’s just the coaching staff and pitching staff, surrounding myself with the other four starters -- quality professional starting pitchers who go about their business the right way.”

Lyles allowed only four hits and a walk and likely would have worked another inning with a manageable pitch count of 86 on the night, but he couldn’t avoid Panik’s 94.8-mph comebacker in the sixth. He walked off the mound shaking his bruised right hand.

“I felt like we might have been better off with another guy out there [in the seventh inning],” Lyles said.

The Pirates gave Lyles and the bullpen plenty of breathing room with an early outburst against a familiar face. Giants lefty Madison Bumgarner recorded two outs on eight pitches to begin the first inning, then Jung Ho Kang worked a seven-pitch walk. Josh Bell followed, jumping on the first pitch he saw to poke a single to right.

That brought up Cervelli, mired in an 0-for-24 slump and sporting a new goatee -- some advice from assistant hitting coach Jacob Cruz -- instead of his usual full beard. He fouled off three pitches from Bumgarner before smacking the eighth pitch of the at-bat to left field for a slump-snapping two-run double.

“It feels like a base hit in the World Series to win. Incredible,” Cervelli said. “Incredible, because what you guys have been seeing is not me. It’s not me. I feel a little embarrassed, but this is the game. We’ve got to figure it out.”

Cervelli immediately came around to score on Pablo Reyes’ single to left, and the two-out rally continued as JB Shuck slapped an RBI single to center to give the Pirates a four-run lead.

“You hear it in Little League all the time: It all started so innocently,” Hurdle said. “Give our guys a lot of credit. The guy on the mound out there is tough, as tough as anybody in the league, and our guys were able to put something up there with two outs, nobody on, then a walk and four straight hits.”

Bumgarner didn’t allow another run, but the cushion was enough for Lyles. The Giants put two runners in scoring position with one out in the second, then center fielder Kevin Pillar lofted a fly ball to right field. Veteran outfielder Melky Cabrera settled under the ball and, with his momentum taking him toward the plate, rifled a 93.3-mph throw that gave Cervelli plenty of time to tag Brandon Crawford as he attempted to score from third.

“He’s played the game for a long time. He’s pretty fundamentally sound,” Hurdle said of Cabrera. “I think he showed some arm strength that maybe wasn’t in a scouting report -- or maybe it was. That throw was on the money. It was quickly launched and gotten rid of, and you saw the footwork. It was a big play for us at the time.”