Lucas Herbert turned in 30 to open up a two-shot lead on a low-scoring day three of the Portugal Masters.
After Oliver Fisher's historic 59 in round two, conditions were once again perfect for the players at Dom Pedro Victoria Golf Course and Australian Herbert was one of many to take advantage as he moved to 17 under.
Tom Lewis - the 2011 champion - was eight under through 12 holes to sit in a share of second alongside fellow Englishman Eddie Pepperell and Swede Marcus Kinhult.
English pair Jordan Smith and Matt Wallace were then five shots off the lead alongside Italian Renato Paratore.
Herbert is playing off invites this season but has a great chance to earn his playing privileges, sitting 103rd in the Race to Dubai Rankings presented by Rolex after four top tens.
Kinhult is 50 places higher after regaining his card via the Challenge Tour last season, while Lewis has finished first and third in the last two weeks on that Tour.
Pepperell, meanwhile, has four top tens in his last six events after winning the Commercial Bank Qatar Masters earlier this season.
Kinhult got off to a flying start, making a birdie on the first and an eagle on the par four second to jump into a share of top spot.
That did not last for long, however, as Herbert made a long putt for an opening gain to edge into the solo lead.
Pepperell made a birdie of his own from five feet on the second to also get to 13 under but Kinhult holed from similar range at the fifth to hit the front on his own.
A brilliant Pepperell approach to the fourth had him back in a share before Kinhult hit an even better one into the seventh for a birdie.
The duo were going toe-to-toe and Pepperell got on the par five fifth in two for another gain to join Kinhult, with Herbert also taking advantage to sit one off the lead.
Fisher's history-making effort on Friday meant that Lewis' excellent 63 went a little under the radar but the 27 year old picked up where he left off, making four birdies in a row from the second to get 11 under.
Another birdie at the seventh saw him turn in 30 and a long putt on the tenth and a brilliant approach into the 11th meant he was just one back.
A long right-to-lefter on the seventh moved Herbert into a share of the lead and he replaced Pepperell who failed to get up and down on the same hole.
The 27 year old hit back from 40 feet on the next but Herbert followed him in to strike out on his own again.
His lead was up to two when he holed a long left-to-righter on the ninth and ahead on the par five 12th, Lewis got on in two to make a third birdie in a row and share second.
Smith was five under through 13 holes, while Paratore and Wallace turned in 33 and 34 respectively.
Englishman Fisher, Finn Mikko Korhonen, Australian Jason Scrivener and South African Richard Sterne were at 11 under.
