Rory McIlroy is two shots off the lead at the midway point of the Charles Schwab Challenge in Texas and feels he's making "improvements" as the week goes on.
The world number one had an eagle and six birdies in a second round 63 to move to nine-under-par at Colonial on Friday night.
"You can do as much practice as you want and play as much as you want at home, but until you actually get into that competitive environment, you're never 100 per cent sure of how your game is," McIlroy told reporters after his round.
"I learnt a lot yesterday and I feel like I made some improvements today on yesterday and learnt a few things. So no, not surprised. I've been playing well at home and I've been hitting the ball the way I've wanted to, just a matter of getting it to translate out on to tournament play, and it's nice that it has.
"This is a golf course that's always let the best players rise to the top. You have to be in complete control of your game, hit fairways, hit greens, convert some putts, and yeah, the leaderboard is a who's who of golf right now. I'm just happy to be in the mix."
Harold Varner III leads the way into the weekend at 11-under while Graeme McDowell and Open champion Shane Lowry both missed the cut.