The way he’d been putting, Seungjae Maeng figured a change couldn’t hurt.

So about a month ago, following the example of a local legend and the advice of his mother, Maeng ditched his old putter for a longer model.

“I was putting so bad and I played with David Ishii and he uses that,” Maeng said. “Out of the blue, my mom was like, ‘you should try that, too.’ ”

The experiment took hold and Maeng’s enhanced feel and confidence on the greens helped him reach today’s quarterfinals of the 103rd Manoa Cup.

Maeng, the medalist in Monday’s qualifying round, birdied the first three holes in his third-round match with Lorens Chan on Thursday. He later ended Chan’s comeback bid by dropping a tricky 6-footer on No. 17 for his fifth birdie of the day in a 2-and-1 win.

“Ever since (the change) my putting and my confidence has improved,” Maeng said. “If I can see the line I feel like I can pretty much make any putt.”

Four high school players remain on Maeng’s side of the bracket with an endurance test awaiting the eight still in contention for the state amateur match play championship.

Maeng, a Moanalua senior, will play Mid-Pacific’s Skye Inakoshi in the quarterfinals this morning. The winner faces either Punahou junior Kalena Preus or Moanalua sophomore John Oda in the afternoon round.

In the opposite bracket, top seed and defending champion David Fink plays 14-year-old Donny Hopoi. Nick Ushijima and Kyle Hayashi meet in the other quarterfinal match.

The final two survivors after today’s play at hilly Oahu Country Club will face another 36 holes in Saturday’s championship match.

“It’s grueling, you feel it going up the back nine,” said Fink, who successfully managed the grind last summer. “It takes knowledge to step away from the ball and not go straight into it right on the tee, but to take some breaths and really relax yourself.”

Last year, Maeng made his way around the course as a caddy for Moanalua teammate David Saka. Taking his own shots this year, he earned the second seed by shooting a 68 on Monday and won his first two matches by relatively comfortable margins.

He maintained his roll with the hot start against Chan, the reigning high school state champion. Maeng made a 10-foot birdie putt on the first hole, two putted for birdie on No. 2 and dropped a 15-footer on No. 3.

“That was my goal in the beginning of the day, knowing Lorens can fire seven birdies like nothing,” Maeng said. “I wanted to grab the lead as quickly as I could.”

Four down through six holes, Chan drew to within one when Maeng bogeyed No. 15. Maeng’s birdie putt on 17 put the pressure on Chan, whose 5-footer slid by the edge of the cup to end the match.

“It’s match play so you just have to keep fighting,” Chan said. “I was close but I missed a few key putts.”

A bit of home-course knowledge helped Fink, an OCC member, sustain his hopes of a repeat title.

Fink had a clear look at the pin from the rough on No. 15. But with two bunkers in front of him and not much green behind the hole, he chipped out to the left, leaving him with a long but manageable putt.

“It was definitely the smarter play, the risk/reward wasn’t worth it,” Fink said. “Where I ended up chipping out was way easier to get up and down.”

Fink cozied his putt next to the hole to save par and took the lead when Todd Rego’s par putt lipped out. He matched Rego the rest of the way for the 1-up win.

He’ll next face Hopoi, the Kamehameha Schools sophomore who is making his fourth Manoa Cup appearance. He first entered at age 10 and is still one of the youngest players in the field.

“Now I feel more comfortable,” Hopoi said following a 4-and-3 win over Isaac Jaffurs, “because there’s more people my age starting to play and doing well, too.”

A birdie putt of more than 30 feet on No. 15 was pivotal in Oda’s 2-and-1 win over Sean Maekawa. Ushijima advanced with a 2-and-1 win over Alika Bell while Hayashi defeated Tommy Yamashita 5 and 3. Inakoshi defeated Matthew Ma 4 and 3 and Preus, the ILH champion, beat Tyler Ota 4 and 2.