Andy Sullivan is closing in on his first win in almost five years at the European Tour's English Championship, while Australian Jason Scrivener is poised for his best finish this season.
Sullivan won three times in 2015 as he finished in Europe's top 10 but he has not lifted a trophy since the Portugal Masters in October of that year.
The 33-year-old Englishman carded a third-round 64 on Saturday that gave him a five-shot lead.
The 2016 Ryder Cup player entered the third day at Hanbury Manor with a one-shot advantage and carded two eagles, five birdies and two bogeys to move to 21-under.
He is five strokes clear of countryman Steven Brown.
South African Brandon Stone (66) is alongside countryman Dean Burmester (69) and Spain's Adrian Otaegui (67) at 15-under.
Best of the Australians is Scrivener at 14-under and a share of sixth.
His five-under 66 on Saturday included six birdies to jump up 10 places on the leaderboard.
Scrivener's compatriot Min Woo Lee is at 12-under tied for 16th after a round of 70 while Scott Hend is well off the pace at six-under.
Sullivan set the tone with a remarkable drive to two feet on the par-four first for an eagle but he needed another eagle on the ninth to reclaim the lead from a charging Stone (67), who had six birdies before the turn.
As Stone faltered on the back nine, Brown became the nearest challenger, signing for a 66 that included him hitting the pin to be denied a hole-in-one on the sixth.
But Sullivan picked up four birdies in six holes from the 12th, with a three-putt on the 13th his only blemish on the back nine.
"My strategy (Sunday) will be the same as today," Sullivan told europeantour.com.
"Just control what I can do. I can't control anyone that is going to come up behind me."
The top 10 players on the European Tour's mini Order of Merit after the first five events of the UK Swing will seal a place in the US Open, with Sullivan having finished fourth at the British Masters two weeks ago.