The second wave of golfers on course for the first round of the British Open at Royal Portrush Golf Club is making a surge up the leaderboard.
Brooks Koepka and Jon Rahm are at the forefront of the golfers challenging Shane Lowry for his spot on top of the tournament.
Lowry kicked off the tournament with a four-under 67, and only Rahm has been able to stay at that number from the afternoon session. Koepka and Tyrrell Hatton were at that number for a time, but then dropped shots on course.
Plenty of players, including six from the morning tee times, have reached three-under. Tommy Fleetwood and Ryan Fox have been able to join that collection of golfers from the latter set of tee times.
While most of the first-round focus has centered on the successful competitors, there are some notable names on the back part of the leaderboard, including Rory McIlroy, who turned in a disappointing round on home soil in Northern Ireland.
British Open Leaderboard
Update as of 12:45 p.m. ET.
Shane Lowry (-4)
Jon Rahm (-4)
Brooks Koepka (-3)
Tyrrell Hatton (-3)
Webb Simpson (-3)
Sergio Garcia (-3)
Alex Noren (-3)
Dylan Frittelli (-3)
Robert MacIntyre (-3)
Kiradech Aphibarnrat (-3)
Ryan Fox (-3)
Tommy Fleetwood (-3)
Full leaderboard can be found on TheOpen.com
Lowry set the tone for the first round with a 67 that featured five birdies and a single bogey, which occurred on the par-four 11th hole.
In fact, the 11th hole is the most difficult on the course Thursday, and it has seen an average score of 4.42.
Most players in red numbers have been able to take advantage of Royal Portrush on the front nine, where five of the eight easiest holes on the Dunluce Course reside.
Koepka was one of many golfers to kick off a strong round at the par-five second, where he carded the first of his four birdies.
The shot that leveled Koepka with Lowry came at the par-four 14th hole, which is one of two par-fours the four-time major winner has finished in three strokes.
Unfortunately for Koepka, he dropped to one shot behind the leaders with his first bogey of the round at No. 17.
Koepka is looking to become the first player to win two majors in back-to-back years since Tiger Woods in 2005 and 2006.
Hatton added his name to the top of the leaderboard with a birdie at No. 17, but he gave that shot back to the course at No. 18.
Rahm joined the leading group with a tap-in for birdie at No. 8. The Spaniard has four birdies and four pars through his first eight holes.
The majority of competitors sitting beneath the top players on the leaderboard completed their rounds in the early afternoon in Northern Ireland.
Previous major winners Webb Simpson and Sergio Garcia headline the pack one back of the leaders, and there are also some terrific stories among the group.
Dylan Frittelli landed a spot in The Open field through his victory at the John Deere Classic last weekend on the PGA Tour.
Frittelli arrived a Royal Portrush on short notice and delivered a three-under 68 with four birdies and a bogey.
While most players at three-under, like Kiradech Aphibarnrat, played with a steady hand, Robert MacIntyre experienced a rollercoaster round with five birdies, four bogeys and an eagle.
Fleetwood filled the former category of the players at three-under, as he has a bogey-free round at the moment.
Louis Oosthuizen and Jason Day are among the golfers two shots behind the leaders. Day is one of a few players in contention with ample time to make up ground since he still has to play the back nine.
Tiger Woods also has nine holes remaining in his round, but he should be worried more about damage control than working his way up the standings.
The 2019 winner at The Masters went through a disastrous stretch that started on the fifth hole with a bogey. Woods carded a double bogey at the par-three sixth and then bogeyed No. 7.
Although Woods' round looks bad, it is far from the worst we have witnessed at Royal Portrush.
McIlroy failed to shine in front of his home crowd with an eight-over 79 that featured a quadruple bogey at No. 1 and a triple bogey at No. 18.
Phil Mickelson at five-over and Adam Scott at seven-over are two of the many golfers with plenty of work to do Friday in order to just make the cut.
David Duval, who won The Open in 2001, recorded the highest score of the first round by shooting a 20-over 91 that included a 14 on the par-five seventh, where he was penalized for hitting the wrong ball.
Follow Joe on Twitter, @JTansey90
Statistics obtained from TheOpen.com