|WGC-Cadillac Championship, R2 leaderboard|
|-9 JB Holmes (US); -7 R Moore (US); -6 A Scott (Aus); Selected others: -2 J Donaldson (Wal); -1 L Westwood (Eng), R McIlroy (NI); +1 S Lowry (Irl); +2 G McDowell (NI); +3 J Rose (Eng); +4 M Warren (Sco), P Casey (Eng), L Donald (Eng); +5 R Fisher (Eng)|
World number one Rory McIlroy threw one of his clubs into a lake during his second round of the WGC-Cadillac Championship in Miami.
The Northern Irishman had just pulled his approach shot into the water on the par-five eighth hole - and sent his long iron after it in frustration.
McIlroy, 25, carded a two-under 70 to lie one under for the tournament.
That leaves him eight shots adrift of leader JB Holmes, who shot a one-over 73 to add to his opening-round 62.
McIlroy's missed cut at last week's Honda Classic was his first since June 2014. He described it as a "kick in the backside".
Speaking at the end of Friday's round, he said he should not have thrown his club into the water.
McIlroy said: "It felt good at the time but now I regret it. Frustration got the better of me.
He told Sky Sports: "Following on from last week, I feel like it's very close and to hit shots like that you get frustrated, but I shouldn't have done what I did."
American Holmes found the water four times and carded a double bogey on the final hole of his second round.
Countryman Ryan Moore is two shots adrift of Holmes after a second-round 71, while Australian Adam Scott another stroke behind.