Cameron Young didn't have as easy of a time in the third round of the Cadillac Championship as he did while building a big 36-hole lead in Florida.

It didn't seem to matter, either.

Young is still in full control at Trump National Doral, after his round of two-under 70 on Saturday (Sunday AEST) got him to 15 under for the week. He has a six-shot lead over a group that includes top-ranked Scottie Scheffler going into a potentially rainy final round.

"No lead is safe out here," world No.4 Young said.

"I'm going to go try to execute my plan as if I'm right around the lead or just trying to have a good day out there, not necessarily with any thought toward where I'm at in the tournament."

Catching Young will be tough in any conditions.

South Korea's Si Woo Kim (69) and Norwegian Kristoffer Reitan (69) also were nine under, with American trio Ben Griffin (68), Nick Taylor (72) and Matt McCarty (69) one stroke further back.

"The tournament's in his hands right now," said Scheffler.

"All I can do is go out and try and have a great round and see where that leaves me."

Min Woo Lee (71) and Adam Scott (66) are both three under in a tie for 23rd, while fellow Australian Jason Day (69) is even.

Young shared the lead through three rounds at the Masters — tying for third at Augusta National after Rory McIlroy beat him by two shots. McIlroy had a six-shot lead after two rounds there and got caught, a lesson that'll be in the back of Young's mind.

"But it won't change really how I play, especially the front nine," added 28-year-old Young.

"I may be a hair more conservative in a place or two, but with the weather looking the way it does, that would be how I would be playing anyway."

Scheffler beat Young by five shots in that final round at the Masters. He'll need to do better than that at Doral if he's going to win.

With AAP.