Sergio Garcia, the 2017 Augusta Masters victor, fellow Spaniard and Rolex Series victor Rafa Cabrera-Bello, American Kurt Kitayama, China's Li Haotong, South African Zander Lombard and Australian Zach Murray are all one shot further back at five-under. Paired in the same group as Koepka, the world number 19 paid for a double bogey on the par-three 12th hole.
Koepka averaged 315 yards off the tee and showed his touch by chipping in on the 17th hole as he closed that side of the course birdie-birdie to go out in 32.
"Everything felt good, and then in Korea, I re-tore it and the kneecap had moved into the fat pad", Koepka told reporters, referencing knee tissue underneath the kneecap.
"I've missed showing up to an event and preparing for something because I haven't had anything to prepare for", he said. "I missed a few putts early on, but drove the ball well and controlled distances really well - that's what you have to do out here". I felt comfortable here and hopefully this one Played well during the week, "said Koepka".
"I have been trying to make sure everything feels right, and it does not feel like my right knee, I'll be honest with you, and it probably won't for a while, " Koepka said. "Just did some treatment on it". It kind of reminds me of when I first came over here to The Challenge Tour and spent a bunch of time here in Dubai.
"I'm very pleased with how I played today. It's nice to be able to take it out and bring it out here".
The Offalyman kicked off a memorable 2019 with victory in this Championship past year, before going on to win his first major when he secured the Open in Royal Portrush.
"I don't want to be out there for six hours, nor does anybody".
Paul Casey is the other member of the group, winning the Abu Dhabi Golf Championship (as it was known then) in 2007 and 2009, while Tommy Fleetwood is the other two-time victor, taking the trophy home in 2017 and 2018.
On a day when a new four-point plan to tackle slow play was implemented for the first time by European Tour rules officials, renowned speedster Paratore signed off with four birdies to set the clubhouse target, which was matched by Norris in the afternoon as he carded nine birdies in a career-best effort on the circuit. Anybody who plays this game knows that a lot of it is built on confidence, a lot of form is built on confidence and that's what I gained from here past year.
"I just didn't have the people that I have around me now, where I can really change going forward".
72-HOLE RECORD: Two-time major victor Martin Kaymer ran away with this event in 2011, the German's 264 total (24-under) delivering victory by eight shots over Rory McIlroy.
The 23-year-old Paratore, looking for his second European Tour win following his triumph in the 2017 Nordea Masters, closed with four straight birdies. "Didn't fall over the first couple of holes", said Norris, who is closing in on a place in the world's top 50, which could earn him a spot at Augusta if he can make the mark by early April.
The effort left the four-time major victor sitting handily-placed in joint-third, just two shots behind the pacestters, Italian Renato Paratore and South African Shaun Norris, in the first Rolex Series event on the European Tour in 2020.