Rory McIlroy insists he is "still right there" at the Wells Fargo Championship despite heading into the weekend five shots off the lead following a disappointing finish to his second round.
McIlroy, who shared top spot after an opening 66, looked set for another good day as he moved to nine under with two holes remaining at Quail Hollow on Friday.
However, the Northern Irishman slipped back towards the chasing pack after dropping three shots on the final two par-fours and having to settle for a one-under-par 70.
Jason Dufner tied his LOWEST career round Friday to secure the top spot @WellsFargoGolf.— PGA TOUR (@PGATOUR) May 4, 2019
Get caught up on Duf’s 6️⃣3️⃣ and more in The Takeaway. 👇 pic.twitter.com/5JA3hDLtPt
That left the world number four on six under overall and in a share for fourth place, five shots adrift of pacesetter Jason Dufner.
Despite the gap, McIlroy is remaining optimistic at the midway stage in Charlotte.
He said on pgatour.com: "I'm still right there going into the weekend. I just need to try and shake off that bad finish and get off to a good start tomorrow."
McIlroy had carded five birdies and one bogey in his opening 16 holes but much of that good work was undone at the death.
On the short eighth - his penultimate hole of the day after starting on the 10th - McIlroy found a bunker off the tee and, despite being only 55 yards to the green, conspired to take another five shots as he recorded a double-bogey.
The four-time major champion, looking to celebrate his 30th birthday this weekend by winning this event for a third time, also bogeyed the ninth - his last - after missing the green and failing to get up and down.
McIlroy was better off the tee on Friday than he was on Thursday but ended up scoring higher. He added: "Golf. It's a funny game.
"I stood up here (Thursday) night talking about how I got the most out of it yesterday, and today was the complete opposite. I turned a 66 into a 70."
American Dufner followed up his opening 68 with a superb eight-under-par 63 that included an eagle, seven birdies and just the one dropped shot as he moved to 11 under.
Max Homa also signed for a 63 - his blemish-free - to sit alongside Joel Dahmen in joint second place on 10 under.
Dahmen, who was overnight leader alongside McIlroy, shot a second successive 66.
Patrick Reed (69) is on six under with McIlroy, while England's Justin Rose (67) and Ireland's Seamus Power (68) are among a group of four players a further shot back.