Northern Ireland's Rory McIlroy birdied three of his last four holes to fire a six-under par 66 and match American Chris Riley for the lead after the first round of the PGA Memorial tournament.
McIlroy has been a contender at the past three majors, sharing third at last year's British Open and PGA Championship and leading the Masters with nine holes to play before finishing with a calamitous 80 and a share of 15th.
After such major misery, a win at the Memorial would feel mighty good.
"It would be fantastic," McIlroy said. "There are 54 holes to go and there's a long way, but I feel as if I am playing good enough to get myself in the hunt come Sunday."
The 22-year-old Ulsterman served notice he intends to be a factor at the US Open in two weeks time at Congressional Country Club in suburban Washington by shining in his opening round in a major tuneup with a world-class field.
"Hopefully I can just keep it going," McIlroy said. "Conditions are perfect out there. You can't really get it much better. Hopefully I can play as well as I did today and shoot another good one tomorrow.
"It could have been a couple better but I will take 66."
McIlroy, who shared 10th at last year's Memorial, began on the back nine and birdied the par-5 11th hole, then answered his lone bogey of the day at the par-4 13th with birdies at the par-4 14th and par-5 15th.
McIlroy, the only player from outside the United States in the top 20 after round one, picked up another stroke on the par-4 third then charged home with three birdies in a row at the par-4 sixth, par-5 seventh and par-3 eighth.
"I got it up-and-down a few times when I really needed to to keep myself at a couple under, and then was able to birdie a few holes coming in, and that was really the difference," McIlroy said.
"I chipped in for birdie on 15, which looked like I was going to do well just to make par, and then up-and-downed it on 16 and up-and-downed it on 17, up-and-downed it on 18 as well. That kept me going."
McIlroy will go to Haiti next week for a UNICEF children's charity appearance -- "It should be pretty eye-opening" -- before playing twice next week at Congressional ahead of the US Open.
"I feel like I'm the sort of age that I can relate to the younger people," McIlroy said. "I just don't want to really put my name to it, I wanted to do something, and they were very keen for me to go and see somewhere where they're sort of hands-on and they're working."
Riley, who also started his round off the 10th tee, birdied the 11th but took a bogey at the par-3 12th. He then reeled off three birdies in a row, parred the par-3 16th, birdied the 17th and took another bogey at the 18th.
Riley, who had not played at the Jack Nicklaus-hosted event since 2002, opened and closed his second nine with birdies and added another at the seventh as well.
"This is my 13th season out here and the first six were great and the next three after that were really not that good, and I'm trying to climb out of a hole right now," Riley said.
Riley's only career title came at the 2002 Reno-Tahoe Open.
"I played solid last year. This year, I've made some cuts and I top-tenned in Hawaii, but it hasn't been that great," Riley said.
"It's just I'm just thinking too much and the less I think the better I do and today I didn't have time to think. The pace of play was so good. I didn't stand around and think about shots. I just played golf."
Chris DiMarco and Josh Teater were one stroke off the pace while a pack on 68 included Rickie Fowler, Steve Stricker, Rocco Mediate, Ricky Barnes, Matt Bettencourt, Dustin Johnson, Stewart Cink, Scott Stallings and Bryce Molder.
Scores on Thursday after the first round of the $6.2 million US PGA Memorial tournament (USA unless noted):
66 - Chris Riley, Rory McIlroy (NIR)
67 - Chris DiMarco, Josh Teater
68 - Rickie Fowler, Steve Stricker, Rocco Mediate, Ricky Barnes, Matt Bettencourt, Dustin Johnson, Stewart Cink, Scott Stallings, Bryce Molder
69 - Hunter Mahan, Matt Kuchar, Charley Hoffman, Shaun Micheel, Ryan Moore, Davis Love, Robert Garrigus, Kevin Chappell
70 - Luke Donald (ENG), Angel Cabrera (ARG), KJ Choi (KOR)
71 - Justin Rose (ENG), Alex Cejka (GER), Aaron Baddeley (AUS), Ernie Els (RSA), Robert Allenby (AUS), Ryuji Imada (JPN), John Senden (AUS), Brendon de Jonge (ZIM)
72 - Charl Schwartzel (RSA), Phil Mickelson, Rod Pampling (AUS), Eduardo Molinari (ITA)
73 - Charlie Wi (KOR), Camilo Villegas (COL), Nick O'Hern (AUS), Brian Davis (ENG), Marc Leishman (AUS), Arjun Atwal (IND), Vijay Singh (FIJ)
74 - Robert Karlsson (SWE)
75 - Martin Laird (SCO), Stuart Appleby (AUS), Thomas Aiken (RSA)
76 - Carl Pettersson (SWE), Mike Weir (CAN), Jin Jeong (KOR), Noh Seung-yul (KOR)
78 - Trevor Immelman (RSA)
79 - Jhonattan Vegas (COL), Henrik Stenson (SWE)
80 - Eugene Wong (CAN)
82 - Matt Jones (AUS)
DQ - Joost Luiten (NED)