Leader Kevin Kisner and Chris Stroud, an unlikely final pairing, were set to tee off at the US PGA Championship as Hideki Matsuyama and Justin Thomas also eyed a maiden major crown.
Kisner, consistent throughout the year's final major at Quail Hollow, was due to begin his final round at 14:45 local time (18:45 GMT) with a one-shot lead.
The American looked comfortable during the third round and had a chance to pull clear before he reached the famed 'Green Mile', perhaps showing some early nerves, double-bogeying the 16th and dropping another shot at 18.
He would tee off with countryman Stroud, the 35-year-old only in the field thanks to his Barracuda Championship win last week.
Still, Matsuyama, who was at six under with Stroud, and Thomas - a further shot back - were favoured to win the Wanamaker Trophy in Charlotte, where hot and humid conditions again greeted players.
World number three Matsuyama admitted to nerves on Saturday after a scratchy two-over 73. He could become the first Japanese player to win a major.
Do you hit one-handed wedge shots during your warm-up?
Hideki does. pic.twitter.com/x546pEUleZ
-- PGA TOUR (@PGATOUR) August 13, 2017
Thomas shot a 59 on the PGA Tour earlier this year and a record-breaking 63 at the U.S. Open, and the American shaped as a huge threat.
South African Louis Oosthuizen, the 2010 Open champion, was alongside Thomas at five under.
The first hole was already offering great chances to players, with 11 birdies made - compared to none a day earlier.
The par-three fourth and par-five seventh, which have provided opportunities throughout the tournament, were also likely to be targeted.
The start of the back nine also offered chances before the 'Green Mile', with 16 through 18 proving tough once again.
World number one Dustin Johnson was the best of those who teed off in the morning, carding a four-under 67 to finish the tournament at even par.
Thundershowers were forecast in North Carolina on Sunday, but it was expected they would miss Quail Hollow.
A three-hole aggregate play-off would be played if required and with a leaderboard packed full of potential first-time major winners and nerves sure to be present, late drama was a possibility in Charlotte.