Brooks Koepka edged a battle of two heavyweights at the WGC-Dell Technologies Match Play, needing a 19th hole to beat world number one Jon Rahm.

The two were paired in the pick of a round of 16 that delivered its fair share of thrills and spills early on Saturday.

Koepka was 2 up twice on the back nine, only to be reeled in by Rahm at the 16th and 17th, meaning an additional hole was required.

A birdie from Koepka was enough as they replayed the 10th, setting up another intriguing quarter-final clash with Dustin Johnson.

For a time, it appeared Johnson would be joining Rahm in making an early exit, as 49-year-old opponent Richard Bland was 2 up through five holes.

However, Bland double-bogeyed the sixth as he lost four of the next five holes, allowing Johnson to canter home 3 and 2.

The other standout match-up saw a replay of last year's final. Billy Horschel won the 2021 title, but he was beaten this time by Scottie Scheffler, who finished 1 up.

Scheffler's next task is against Seamus Power, who this time last year was finishing in a tie for 54th at the Corales Puntacana Resort and Club Championship, leaving him ranked 463rd in the world.

On Saturday, Power routed Tyrrell Hatton 4 and 3 – albeit not the biggest win, as Abraham Ancer dominated Collin Morikawa 7 and 6 and will face Corey Conners, a 5 and 3 winner.

In the final section of the draw, Will Zalatoris required 22 holes to get the better of Kevin Na, with Kevin Kisner up next.