Ben Hartz was only worried about what he could control.

But the Butler BlueSox starting pitcher knew what a loss to the Prospect League East Division leading Chillicothe Paints Thursday night would have meant.

“Knocked out,” Hartz said.

Hartz and reliever Austin Ross slammed the door in a 1-0 Butler win over Chillicothe at Kelly Automotive Park.

“I wanted to come out and help the team win,” said Hartz, who is now 3-0 with a 1.14 ERA. “That’s all that was on my mind.”

The team with the East Division’s top record after 30 games will clinch a playoff spot as the first- half champion. The Blue Sox (15-10) are 1.5 games behind Chillicothe (16-8). Winning also kept Butler kept ahead of the hard-charging West Virginia Miners (14-12), who have won five straight.

Butler has never made the playoffs.

The BlueSox will host the Paints again tonight.

“I told the guys yesterday the end of the first half is coming up and the first-half winner gets an automatic bid to the playoffs,” Butler manager Anthony Rebyanski said. “I said there’s no pressure, let’s go out and do what we’ve done all year. We did just that. We stole some bags and made good plays in the field.”

While the BlueSox and Miners have tightened up the division race, Paints manager Greg Cypret isn’t ready to panic.

“We have to look at it like all the games mean the same thing,” Cypret said. “We know the standings and the situation, but we just have to come out and play a better baseball game.”

Butler shortstop Zac LaNeve, first baseman Ryan Uhl and catcher Russell Clark teamed up to prevent Chillicothe from forcing extra innings.

In the ninth, Dawson crushed a double off the left-field wall with one out. Dawson ended up on third after the throw missed the cutoff man.

T.J. Diffenderfer followed by hitting a grounder to short, which LaNeve relayed to Uhl for a force out.

Uhl then fired the ball home to Clark, who tagged out a sliding Dawson to end the game with a 6-3-2 double play.

“As soon as he threw it, he started taking off and I got a little scared,” Ross said. “But Uhl made the play and Russ made the tag.”

Butler won despite not taking advantage of Chillicothe’s mistakes.

The Paints walked four batters and hit two batters with pitches.

The BlueSox had four hits and left seven runners on bases and left the bases loaded in the fourth.

“I thought our pitchers competed like crazy tonight,” Cypret said. “We have to do a better job all-around, inning by inning. I felt there were too many innings where we didn’t put any pressure on them at all.”

LaNeve scored the BlueSox’s lone run in the third. He led off with a walk against Paints starting pitcher Patrick Riehl.

Riehl plunked Clark to move LaNeve to second base. Stephen Sada then sacrifice bunted and the throw to first went wide, allowing LaNeve to score.

The Paints threatened in the seventh when Joe Hoscheit reached on an error and Dawson singled to start the inning off Hartz. Rebyanski went to Ross, who struck out the next two batters and induced a groundout to end the inning.

“I knew I had to shut the door the last three innings because our bats are struggling,” Ross said. “We have good hitters and it will come around.”

Chillicothe 000 000 000 — 0 5 1

Butler 001 000 00x — 1 4 1

W: Ben Hartz 6IP (3K, 1BB). L: Patrick Riehl 4IP (1K, 3BB). S: Austin Ross 3IP (3K, 0BB)

Chillicothe (16-8): Ronnie Dawson 2-1B 2B, Matt Hopfner 1B, Kurt Hoekstra 1B.

Butler (15-10): Stephen Sada 1B, Forrest Perron 1B, Nick Sell 1B, Zac LaNeve 1B.

Friday: Chillicothe at Butler