Shane Lowry finished well to card a 1 under par round of 71 on day one of the Masters at Augusta, as his playing partner Justin Rose shot 65.
England's Rose holds a four-shot lead on seven under par over American Brian Harman and Japan's Hideki Matsuyama.
Olympic champion Rose lost in a play-off to Sergio Garcia in 2017 and is holding his fourth lead or co-lead after the opening round of the Masters.
As Rory McIlroy slumped to a 4 over par round of 76, Lowry found himself as one of only 12 players under par on a tricky day.
The Offaly native got to the turn in 2 under, before making a double bogey on the difficult 10th.
He then chipped his third shot into the water on the par-five 15th hole before rallying with birdies on 16 and 18.
Lowry really enjoyed the firm and fast conditions which greeted the players.
"Look, I felt like I played good. I had a couple of bad errors, 10 and 15 were a bit silly, but I was very kind of proud of myself the way I hung on.
The golf course was -- oh, my God, I've never seen it like that, which was great. I loved it. I've always wanted to play Augusta like this in the Masters, firm and fast and putts getting away from you. Even though I had a 15-footer on 8 there, chance for birdie, and you're just trying to lag it down to the hole. Same on 17. Yeah, it's not very enjoyable when you're doing it, but when you look back on it, it's like, yeah, that was pretty cool."
Rose won the 2013 US Open and is back working with coach Sean Foley.
The 40-year-old played his last 11 holes in a staggering nine under par, and he says his great round was down to his work on the greens.
"I putted the ball beautifully and read the greens unbelievably well. If you had said to me walking up the 8th hole, I'd have said no chance, this course is playing a little too tricky for that. But it's incredible. It's a good reminder that you just never know what can happen out there, just to stick with it on the golf course."