Hideki Matsuyama breaks out of mini slump with seven-under 65 to grab a share of the lead at the Memorial Tournament

After getting over a nagging wrist injury, it's been a slow climb back for Hideki Matsuyama, who showed some signs of life in his most recent start, finishing T-16 at the AT&T Byron Nelson. Hardly anything newsworthy for a player that amassed four victories and more than $12 million in earnings in his last two seasons on the PGA Tour, rising as high as No. 2 in the Official World Golf Ranking.

On Thursday, Matsuyama looked to get fully back on track at Muirfield Village, the site of his first PGA Tour victory in 2014. Jack's place proved to be the slump buster he needed, as he carded a seven-under 65 highlighted by an five-hole stretch of six under par on his final nine, giving him a share of the Memorial Tournament lead with Abraham Ancer and 19-year-old Joaquin Niemann.

A front-nine 33 set the tone for what appeared to be a low round for Matsuyama, but things quickly went backwards at the turn, beginning with a bogey at the par-4 10th. At the 11th, his second shot came up short and well right of the green, and he proceeded to shank his third 25 yards further to the right, eventually making a second straight bogey and dropping to one under on his round.

But momentum shifted at the 13th, where he began a stretch of four consecutive birdies and capped it off at the par-4 17th with an eagle hole-out from 137 yards with a gap wedge. A par at the 18th gave him his third score of 66 or lower in his last four rounds, a sign that he may be finally rounding into form.

"It has been frustrating," he said. "In the past even if I wasn't playing well, I could still get it around, get it in the hole. So the last couple of months have been trying. I'm just really glad that I was able to play well today and post a good score at the start."

Niemann, meanwhile, has made quite the first impression in his limited starts as a professional, the 19-year-old from Chile finishing solo sixth in his debut at the Valero Texas Open and tying for eighth at the Fort Worth Invitational. As for Ancer, he's got a bit more experience, having already competed in 39 tour events and collecting seven top-25s. But this is his first start at the Memorial, although he's been here before.

"Actually have great memories of this place," Ancer said. "My freshman year of college [at Odessa Junior College] I got the Jack Nicklaus Award and I got to come here as a freshman, Sunday, and get that award from Jack. That was incredible, and it was like deja vu walking the fairways, watching from outside and now playing. It's a dream come true obviously. And today I felt great. I hit the ball really good off the tee, hit my irons well, and I putted well and I scrambled really good. So when you do that it's usually a pretty good round."

Alone in fourth is Beau Hossler, who posted a six-under 66, his seventh opening round of 68 or lower on tour so far in his rookie season. Unfortunately, he's had some trouble on the weekends, except at the Houston Open, where he finished runner-up to Ian Poulter. He hopes to duplicate that, or even top it, this week.

"The reality is I just need to be more consistent round one through four," Hossler said. "Whatever days I'm struggling on I need to do better on those days.

"I played great on the weekend in Houston, pretty much flawless, really. I have tons of confidence from closing out tournaments from junior and amateur golf and college golf. It's not a concern of mine. Obviously I noticed a trend, but at the same time I think I'm on the right track and I've just got to stick with what I'm doing."

Among the marquee names in the field, only Jason Day was able to put himself in the mix, firing a four-under 68 to get within three shots. Tiger Woods (72), Dustin Johnson (72), Rory McIlroy (73), Phil Mickelson (73) and Jordan Spieth (75) will have much work to do on Friday to make the weekend.