PALM BEACH GARDENS, 26 Feb 2015 (AFP) - Given the daunting conditions, which saw only 19 players break par, the Northern Irishman wasn't too disappointed with an effort that left him eight shots off the pace set by Web.com Tour graduate Jim Herman.
"I'm coming off a three-week break, tough conditions to come back in," McIlroy said.
"Today wasn't what I wanted to start with, but if I can get it into red numbers tomorrow I'm right back in the tournament."
McIlroy opened with a double-bogey at the first hole of the par-70 PGA National layout, unable to find his tee shot that landed in the brush.
McIlroy pulled back a shot with a birdie at the third, but then made bogey at the fourth and double-bogey from the water at the fifth.
After a birdie at the eighth, McIlroy stumbled to bogeys on 11 and 14 before salvaging his round with a birdie-birdie finish.
"The wind started to die down for us the last few holes," said McIlroy, who said he told playing partner Brooks Koepka as they headed toward the 15th tee, "Let's just make a couple birdies on the way in, try to get something out of it."
Koepka, winner of the Phoenix Open earlier this month, ended up signing for an eight-over 78 while Dustin Johnson, the third man in the group, posted a 77.
McIlroy, coming off a victory in the Dubai Desert Classic and a runner-up finish in Abu Dhabi in his first two European starts of the season, managed to finish on a better note and was optimistic of more improvement Friday.
"I looked at the forecast for tomorrow morning ... it looks nice. Hopefully the conditions will be a little easier," he said.
The struggles of McIlroy and so many others only made Herman's round look all the more impressive.
Herman, who lives in nearby Palm City, played without a bogey in the morning wave.
Herman, who has one career victory on the Nationwide Tour, now the Web.com Tour, at the 2010 Moonah Classic in Australia, earned his 2015 tour card through last year's Web.com Finals Series and has made the cut in six of his first 10 events this season.
"The wind is very challenging," said Herman, who posted one of just two bogey-free rounds on Thursday.
"When you get it down wind you have to take advantage of it. The par-fives are very doable. I was able to get home on 18 ... When you do get down wind you have to take advantage of it."
Herman had a one-shot lead over fellow American Brendan Steele.
Ireland's Padraig Harrington shared third place on three-under 67 with Americans Martin Flores and Patrick Reed.
Leading first-round scores on Thursday in the US PGA Tour $6.1 million Honda Classic (USA unless noted, par-70):
65 - Jim Herman
66 - Brendan Steele
67 - Padraig Harrington (IRL), Martin Flores, Patrick Reed
68 - Daniel Berger, Scott Piercy, Martin Kaymer (GER), Rory Sabbatini (RSA), S.J. Park (KOR), David Lingmerth (SWE), Jamie Donaldson (WAL)
69 - Ben Crane, Zach Johnson, Michael Thompson, Brendon de Jonge (ZIM), Russell Knox (SCO), Luke Donald (ENG), Paul Casey (ENG)
70 - Thomas Bjorn (DEN), Nicholas Thompson, Sean O'Hair, Brian Harman, Rickie Fowler, Matt Every, Charles Howell, Jason Kokrak, John Huh, Robert Garrigus, David Hearn (CAN), Lucas Glover, Ben Martin, Alex Cejka (GER), Freddie Jacobson (SWE)