SYLVANIA, Ohio -- Allison Walshe relied on her putter Thursday to grab the lead after the first round of the LPGA Marathon Classic with a 6-under-par 65.
Walshe needed just 22 putts to complete the best round of her career at Highland Meadows Golf Club. She one-putted 11 holes.
"I think the difference for me today was definitely my putting," Walshe said. "I struggled with it last week and came out here and did a lot of work with it.
"Coincidentally, I three-putted the first hole and I was like, 'Here we go again.' One-putted the next hole and just got my confidence going and made a lot of putts."
Paula Creamer, 18-year-old Lexi Thompson and Jessica Shepley were tied for second at 5-under-par 66.
Inbee Park, the world's No. 1 ranked player and winner of her last three tournaments, was in a group of five at 4-under 67.
Defending champion So Yeon Ryo shot a 68 and was tied for 10th.
The rest of Walshe's game felt in sync coming into the tournament, but improving on the green was something she made a priority -- specifically getting the speed right.
"I've been hitting it probably the best I've been hitting it in a long time," she said. "I've been giving myself a lot of opportunities and it's been frustrating because I haven't been able to go real deep and make some putts."
In an effort to clean up her stroke, Walshe worked with putting coach Joe Hallett. She finished with eight birdies, including a chip-in on No. 14.
"He's out here this week and we actually did a lot of work with it," Walshe said. "We did an article for somebody yesterday on putting, coincidentally, and so we got to grind on that a little bit. He looked at it and I had some extra thoughts in my head which obviously paid off."
Players battled hot and humid conditions all day as the heat index approached 100 degrees.
"I kind of liked my draw of being in the morning today," Walshe said. "The heat is the heat, we're going to get it in the afternoon tomorrow. I think it will be kind of a grind to sweat out there all afternoon, go to bed and do it all over again the next day."
Creamer appeared to be on her way to tying for the lead or taking over first place with a birdie to go 5 under with five holes remaining.
After a bogey halted her charge up the leader board, she bounced back with a birdie at the par-3 sixth - her 15th hole of the day -- to get back to within one of the lead. On the final hole, Creamer stuck her approach about 10 feet from the cup but missed the putt and her chance to tie for the lead when the ball rolled by the left side of the hole.
Despite the disappointing par on her last hole, Creamer was satisfied with her round.
"I missed a couple coming down the stretch, but I kept giving myself opportunities," she said. "I had a lot of shots out there that I could have gone lower with, but at the same time, it was a good start.
"I haven't been able to start off the way I wanted in the last couple events, so this was nice to post a good number."
Thompson got off to a shaky bogey-bogey start but played her final 16 holes in 7 under par.
"I started off pretty bad," Thompson said. "I missed a few putts in the beginning. I just tried to not worry about it too much, I knew there were a lot of birdie chances out here, so I just let it go and hit a few good shots coming in and then went for the last few par-5s and made birdies."
Park, who started on the back nine, parred her first seven holes before making a birdie at the par-5 17th. She found a groove on the front nine and had birdies at Nos. 5, 7 and 9 to gain some momentum heading into the second round on Friday.