Justin Rose held a one-shot lead in Rio de Janeiro as the third round of the Olympic Men's Golf Competition moved towards its conclusion at the Olympic Golf Course.
The Briton made two eagles in his first five holes to get to ten under and five pars followed to maintain a slender advantage over overnight leader Marcus Fraser.
The Australian turned in 36 to sit a shot ahead of Frenchman Grégory Bourdy and Swede Henrik Stenson, with Bubba Watson Emiliano Grillo and Thomas Pieters a further shot back.
Belgian Pieters gave a signal of his intent when he bombed his drive 379 yards down the first to help set up an opening birdie and join Fraser at the top of the leaderboard.
The two-time European Tour winner and Fraser both got in trouble off the tee on the second but while Fraser was able to save his par, Pieters dropped back to nine under.
That was only one ahead of Rose who - after starting birdie-bogey - holed a chip on the third for an eagle and, when Pieters three-putted the same hole, Fraser had a two-shot lead.
That cushion did not last long, however, as Fraser got in bunker trouble off the tee on the fourth to drop a shot with Stenson also making a bogey to drop to seven under.
Ahead at the par five fifth, Rose then hit the green in two and rolled in an 18-footer to take the outright lead while Bourdy also made a birdie.
Stenson holed putts of 60 and 108 feet in round two and he got the putter going again, rolling in for an eagle from 30 feet on the fifth and a Pieters birdie meant there was a three-way tie for second.
American Watson had moved himself up the leaderboard with four birdies in his first five holes and when he added another gain on tenth, he was just three off the lead.
Bourdy moved out of that group with a birdie on the sixth but Pieters headed in the other direction as a ragged tee-shot and bunker trouble on the seventh saw him record a double-bogey.
Stenson fell back into the bunch at eight under with a bogey on the eighth and that was just a shot clear of Argentinian Grillo, who made a sixth birdie of the day on the 12th to go with two bogeys.
Denmark's Thorbjørn Olesen made back-to-back birdies on the tenth and 11th to get to six under alongside Graham DeLaet, a shot clear of Spaniard Rafa Cabrera Bello, Finn Mikko Ilonen and Austria's Bernd Wiesberger.
American Rickie Fowler set the clubhouse target at three under after turning in 29 as he signed for a brilliant 64.
Jaco Van Zyl followed Rose into the record books as he made the second hole-in one in Olympic history.
The South African withdrew from The Open Championship and the US PGA Championship to focus on his preparations for Rio and he holed his tee-shot on the 173 yard eighth hole for the 30th ace of the European Tour season.
It's great. Especially when you add it up, the least amount of strokes you can take, it really helps. It's just really special - Jaco Van Zyl
"The pin was cut back left just over the trap there and I just absolutely pured a seven iron," he said.
"I looked at it the moment it came off the face. I hit it to about three inches there on the same hole in the first round and I chatted to my caddie and I said, 'there's something special going on in the Olympics', and lo and behold, two rounds later, we managed to hole in one."
Rose became the first man in Olympic history to hole a tee-shot when he aced the fourth on Thursday.
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