Troy Merritt shot a two-under-par 69 to take a three-stroke lead into the final round of the US PGA Tour’s RBC Heritage, while defending champion Matt Kuchar and Masters winner Jordan Spieth stayed within reach.

A day after tying the course record with a 61 to build a four-stroke advantage at Harbour Town, American Merritt had four birdies and a double bogey to reach 14-under-par 199.

Kuchar, Brendon Todd and Kevin Kisner were tied for second.

Todd made the big move with an eight-under 63, the day’s lowest round, while Kisner shot a 67, and Kuchar a 68.

Jim Furyk led a group another stroke behind after a three-under 68, with Spieth five shots back at nine under, also following a 68.

Spieth believes he can shoot even lower on Sunday to chase a second straight jacket, this one tartan.

“There’s a low one out there and I think it’s certainly possible” to win, the Masters champion said.

Only Bernhard Langer in 1985 followed a Masters win with success at the RBC Heritage.

Merritt one-upped Spieth’s round on Friday with a 61 to tie the tournament’s course record set in 1994 by David Frost.

It moved Merritt to the top of the leaderboard and looked like it might give him a strong jump start to keep things going on Saturday.

And Merritt opened birdies on the second and third holes to move to 14 under.

But a double bogey on the par-4 eighth hole bounced him back down.

Merritt eventually regained that edge with a birdie on the ninth hole and on the par-3 14th hole after knocking his tee shot within four feet.

He made pars the rest of the way and will take to the course on Sunday seeking his first career PGA Tour victory.

Cameron Smith had a round of four under to be five under for the tournament and the best-placed Australian in a tie for 27th.