UNIVERSITY PARK — Clay Holmes allowed one hit Thursday against Williamsport.

He might not forget about it when he arrives to work today.

The perfectionist in Holmes dissects his outings, an atypical habit for a 19-year-old six starts into a professional career.

Holmes pitched five more scoreless innings to lead the Spikes past the Crosscutters 7-4 Thursday at Medlar Field at Lubrano Park. The right-hander retired 15 of the 16 batters he faced. But Yan Carlos Olmo ripped a single off the mound with two outs in fifth, giving Holmes something to ponder.

“You can always improve,” he said. “You can’t always look at stats. I’m trying to go out there and not give up a hit. I’ve come close the past few times, especially with two outs there, and I was ahead 1-2 in the count and just didn’t get the ball in enough. That’s something that will definitely linger in my mind.”

The hit didn’t fluster Holmes. His 61-pitch outing ended with Brian Pointer bouncing out to second baseman Yhonathan Barrios.

The start marked the second straight time Holmes carried a no-hitter into the fifth. His recent lines look like something placed under a copier. He has lasted five innings and allowed one hit in each of his past three starts.

His performance Thursday lowered his New York-Penn League-leading ERA to 0.94, a sign the Pittsburgh Pirates are starting to get a return on the $1 million they needed to sign Holmes last summer.

“The biggest thing for me is his mentality, attacking hitters and staying out of locate mode and staying into aggressive mode,” pitching coach Justin Meccage said. “You saw a good downhill fastball, and the big thing tonight that was a little bit different was that he had the ability to put people away with a change-up and breaking ball mix.”

Holmes whiffed four hitters, his highest strikeout total since equaling the number June 27 at Batavia. He ended Thursday’s second by striking out Mitch Walding and Olmo. He then used an off-speed pitch to finish 2011 Philadelphia Phillies first-round draft pick Larry Greene in the fourth. Enhancing his change-up and curveball are focuses of Holmes’ between-start bullpen sessions.

“We work on that in the bullpen, not only locating that curveball but throwing it with some aggression and down in the zone,” said Holmes, a ninth-round draft pick last year who bypassed a scholarship to Auburn to sign with the Pirates. “That’s when you usually gets your swing and misses. That was there tonight when I got a chance to throw it.”

A free-swinging opponent was standing 60 feet, 6 inches from Holmes. The Cross-cutters entered the game with a league-high 272 strikeouts, and they didn’t make Holmes labor. Holmes didn’t throw more than 14 pitches in any of his five innings.

Offensively, the Spikes built on their nine-hit performance in Wednesday’s 7-3 victory at Mahoning Valley. The Spikes (16-15) scored three runs off Williamsport stalwart Josh Warner in the first inning and expanded the lead by scoring twice in the fifth.

Catcher Jacob Stallings had hits in first three at-bats. He doubled in the second and singled in the third and fifth innings. Shortstop Chris Diaz, who batted behind Stallings in Dave Turgeon’s order, went 2-for-3 with three RBIs.

The Spikes prolonged multiple innings, scoring their final four runs with two outs. Walker Gourley’s two-out double in the sixth expanded the lead to 7-0.

“It’s huge and we started that in Mahoning Valley,” Turgeon said. “We did a lot of damage with two outs, big two-out knocks. Those are back-breakers for guys.”

Williamsport’s Chris Serritella hit a two-run homer off Logan Pevny in the seventh. Doubles by Cameron Perkins, Greene and Serritella off Tom Harlan cut the lead to three runs in the ninth.

The teams continue their four-game series tonight at Williamsport’s Bowman Field.

Notes: Pitcher Clario Perez and outfielder Gavi Nivar joined the Spikes on Thursday. Perez, 19, went 1-1 with a 5.84 ERA in 242/ 3 innings at full-season West Virginia. Nivar, 22, hit .294 with six RBIs in 14 rookie Gulf Coast League. The Pirates also released Spikes outfielder Rodarrick Jones, a 2011 37th-round draft pick who was hitting .128 in 14 games.

Guy Cipriano can be reached at 231-4643. Follow him on Twitter @cdtguy