Lucas Bjerregaard fired a 65 to set the clubhouse target on day two of the Portugal Masters.
The big-hitting Dane looked close to making his European Tour breakthrough in 2015 with four top fives in his last nine events and is in need of another big finish this term.
He currently sits 114th in the Race to Dubai Rankings presented by Rolex but was blemish-free on Friday as he got to 11 under to hold a two-shot lead.
South African George Coetzee, Ireland's Shane Lowry and Englishman Eddie Pepperell were his closest challengers, with Ashun Wu and Joost Luiten out on the course at seven under in the very early stages of their rounds.
Danny Willett made a welcome return to form with a 65 to sit in a group at six under that also contained fellow Ryder Cup player Victor Dubuisson and South Africa's Thomas Aiken, who posted the lowest round of the week so far with a 63.
Bjerregaard had battled his way to a 66 despite finding the water twice on day one but his job was far more straightforward in round two with birdies on the fourth, fifth, seventh, eighth, 12th and 17th.
Lowry claimed his first professional win here in 2012 after a stunning amateur triumph at the 3 Irish Open three years earlier and Dom Pedro Victoria Golf Course once again proved a happy hunting ground.
Birdies on the 12th, 13th and 15th saw him turn in 33 from the tenth and he made further birdies on the second and fourth before a five-footer on the fifth had him within touching distance.
A dropped shot on the difficult seventh threatened to stall his momentum but a 25-footer on the eighth and approach to eight feet on the ninth moved him alongside Pepperell and Coetzee.
South African Coetzee held a share of the overnight lead with Luiten and a round of 69 kept him right in the mix.
Playing partner Pepperell had arrived in Portugal last year fighting to keep his card and just missed out before regaining his playing privileges at the Qualifying School.
He is comfortably inside the top 100 this season and a 67 had him in a good position to challenge for a first European Tour win.
Coetzee birdied the second but gave the shot back on the sixth before making a gain on the tenth, holing from 30 feet on the 16th and saving par after finding the water on the next.
Pepperell made a birdie-birdie start and added further gains on the 11th and 14th.
China's Wu was one under for the day after two holes while Dutchman Luiten was level after one.
By his own admission Englishman Willett has been struggling for form since he won the Masters Tournament in 2016 but he produced his first sub-70 European Tour round since the Maybank Championship in February to move into contention.
France's Dubuisson has made it to the weekend just four times so far this season but will be sticking around in Vilamoura after a 68 that saw him join Willett, Aiken, Laurie Canter, Scott Jamieson, David Lingmerth, Marcel Siem, Richard Sterne and Jonathan Thomson five shots off the lead.
Aiken had bogeyed the third but then made nine birdies in 12 holes from the fifth before a bogey-birdie finish.
