That left the Northern Irishman at four-over 144, one stroke outside the cutline.
"It was the wrong time to make a bad swing on the tee and it put me in an awkward spot".
Make that two errors. He was breezing through the round, looking like a safe bet to carry the lead into Sunday when out of nowhere he quadruple-bogeyed the 15th hole thanks to two shots landing in the water.
Sergio Garcia and Adam Scott were threatening to turn the Honda Classic into their own private duel as Rickie Fowler's quest for perfection quickly came to an end at PGA National. "I'm in no shape to play golf", he said. "I've played better every day this week, and it started pretty good". "Moreso than getting to minus nine (under par) to pick a shot back after a disappointing quad was important".
Scott saw a three-stroke advantage disappear when he found the water twice at the same hole along PGA National's infamous Bear Trap, but recovered to post a four-under 66 and share the advantage with Garcia.
Asked if he expected it to be a two-man race the rest of the way, Garcia said "Not at all".
Rickie Fowler had a one-shot lead going into the third round and was the first player at the Honda Classic to go bogey-free through the opening 36 holes. "It's not that easy to make birdies out there, but it can be done".
American golfer Jason Bohn was in hospital Friday night after suffering a mild heart attack following his second round at the PGA Tour's Honda Classic. He didn't have a bogey in the first two rounds of this tournament; he started off with back-to-back pars before the wheels started to fall off.
Garcia, playing alongside Fowler and USA Ryder Cup captain Davis Love III, could not match the heights of his first-round 65 but a battling 69 kept him within striking distance of the leader. That left the two tied for the 54-hole lead at 9-under.
So far, the 18th hole has been kind to him. We'll see how the day goes. And to compound it is not good, so pretty costly, but fortunately, had a couple shots to spare.
Graeme McDowell had a 67 and was 6 shots behind at 207, along with Scott Brown and Vijay Singh (68).
But McIlroy will have the weekend off for the second consecutive season after he undid a lot of hard graft with a triple-bogey six at the short fifth - his 14th hole of the round. His problem was the golf ball hit the putter four times from 20 feet.
Scott was mostly terrific en route to shooting a 66.
Fowler was at 8-under 132, one shot ahead of Jimmy Walker, who finished his round of 66 with a 25-foot birdie on the 17th and a 40-foot eagle putt on No. 18.
He rolled in a 22-foot birdie putt at his final hole and Walker, playing behind him, heard the roar but stayed in touch with his strong finish.
"That's a big accomplishment around this golf course - not just one day, but back-to-back", Fowler said.
Scott was quietly going about his job through two rounds. "The wind was not as much as yesterday but it was still challenging", said Garcia. 5 and 6, but rallied with four birdies, including on the par-3 12th.