Australian Marc Leishman recorded a 3-under-par 68 to extend his lead to five strokes Saturday at the BMW Championship in Lake Forest, Ill.
Leishman, who resides at 19-under 194 for the tournament, is comfortably ahead of countryman Jason Day and American Rickie Fowler heading into the final round at Conway Farms.
The 33-year-old Leishman is 18 holes from his third PGA Tour victory and his second this year, following his win at the Arnold Palmer in March. Should he stave off the field on Sunday, Leishman will secure one of the top five seeds at the Tour Championship next week while the top 30 advance to the tournament itself.
Leishman's 194 is one stroke behind the tournament-best total that Day recorded in 2015. Leishman's total, however, serves as his best 54-hole mark on the PGA Tour.
Leishman shared the 54-hole lead at the Dell Technologies Championship TPC Boston two weeks ago with Justin Thomas, who surged ahead in the final round to win the event.
"Putting four good rounds together (is the biggest challenge)" Leishman said, according to CBSSports.com. "A lot of tournaments you put three rounds together. May not be in a row. Very easy to throw a mediocre round in there. Tomorrow I got to try not to do that.
"After what happened at the Dell, I got extra determination to finish this one off and my game is in a better spot. I feel like this course sets up for me a little better than it did at Dell. Hopefully I can just play well, do the right things and not worry about the result too much, as hard as that will be."
Day, who won the tournament in 2015, and Fowler each carded a 70 on Saturday. Day closed within two shots at the turn before collecting eight pars and a bogey on the back nine.
"Bit of a grind out there today," Day said. "I thought with the pin locations, looking at them this morning, I felt there was an opportunity to shoot a low score, which there was. To be honest, to only have one bogey -- obviously I missed opportunities out there like a couple on the last two days. I missed those today and, unfortunately, shot 1 under. With the way I was hitting it, I'm actually quite happy."
Day, however, knows that overcoming Leishman could be a tall order on Sunday.
"Leish is playing spectacular," Day said. "Quite happy with how he's happy because we're on the Presidents Cup team together but saying that, I mean he's going to be very difficult to beat tomorrow. I got to come out and play really good golf because he's not making any mistakes. (He's) hitting it on the greens and holing putts. That's a good formula for success and it's going to be tough tomorrow."
Fowler got off on the right foot by sinking a 25-foot eagle putt on the opening hole, but mustered just one birdie the rest of the day. He failed to convert putts from approximately six feet away on consecutive holes on the back nine.
Britain's Justin Rose shot a bogey-free round and finished with a 66 on Saturday to reside in fourth place, seven strokes behind Leishman.
Spaniard Jon Rahm carded a 65 in the third round to pull himself into a seven-way tie at 11 under. Others included in that mix are Scott Brown, Ryan Moore, Charley Hoffman, Chez Reavie and Matt Kuchar -- who each shot a 67 on Saturday -- and Patrick Cantlay (70).
Phil Mickelson shot a 69 on Saturday, marking his seventh straight round in the 60s. He sits at 9 under for the tournament.