Rory McIlroy fired an impressive four-under-par 68 to lie six shots behind leader Thomas Bjorn after the first day of the PGA Championship at Wentworth.
McIlroy admitted afterwards that it had been "very difficult to focus at times" one day after he announced the end of his engagement to Caroline Wozniacki.
"I'm just burying my head in my golf and for the most part I did that pretty well today," said the 25-year-old.
McIlroy carded eagles on the seventh and 12th holes during his round.
The Northern Ireland player holed his wedge shot from 130 yards for a two at the par-four seventh and followed that up with a three at the 12th, missing out on an albatross by a matter of inches following a five-iron approach from 203 yards.
The two-time major champion also posted birdies at the fourth, sixth and 18th holes, but dropped two shots on his outward nine and another at the par-five 17th.
"It's going to be a very tough week and I am just trying to put my head fully into my golf," admitted McIlroy afterwards.
"I think it's only natural, I don't think you would be human if it wasn't tough, especially when it's a little slow out there and you are waiting between shots.
"I haven't turned on my phone for a few days and I've given my laptop away, I'm sort of living like I'm in the 70s."
McIlroy's task was made harder by two weather delays caused by the threat of lightning, the second of which came after he had played just one hole.
"It's always nice to make two eagles in one round, I can't remember the last time I did that," McIlroy added. "I've never had an albatross, that's one thing my dad still has over me.
"Four under has got me in the top 10 (joint eighth) which is a pretty rare position for me in this tournament. I would just be delighted to make it to the weekend because I haven't done that the last two years."
Bjorn equalled the course record with a 62 to enjoy a two-shot advantage over nearest challenger, Ireland's Shane Lowry, at the flagship event of the European Tour.
Lowry's opening 18 holes included 10 birdies, six of which came on his inward nine, with just two bogeys marring his card.
McIlroy is tied for eighth position, with Michael Hoey next best of the Northern Ireland contingent on one under.
Darren Clarke has work to do to make the cut on three over, while Ballyclare's Gareth Maybin is two shots worse off on five over.
Padraig Harrington is well in contention in the upper part of the leaderboard on three under, with Damien McGrane one under, European Ryder Cup captain Paul McGinley and Simon Thornton two over, and Peter Lawrie three over.