World Number 670 Julien Guerrier has a leadership lead in Portugal -14 J Guerrier (Fra); -9 K Sihwan (USA); -7 L Johnston (Sco), S Vincent (Zim), A Saidder (Fra), M Jordan (Eng), M Simonsen (Den), A Meronk (Pol), M Armitage (Eng), W Nienaber (SA), A Rozner (Fra); Selected others: -6 J Donaldson (Wal); -3 T Fleetwood (Eng); -1 S Gallacher (Sco)
Scot Liam Johnston slid from the top to tie for third when French Julien Guerrier shot a five lead took part at the Portugal Masters halfway through the stage.
World number 670 Guerrier, in view of a first European Tour title, is 14 under par after his 61 with a 66.
The American Kim Sihwan is in second place, while Johnston (74) and the English couple Matthew Jordan (69) and Marcus Armitage (67) are nine players at the bottom seven.
"I saw the bite of the track today," said Johnston, who opened with a 61.
"I'm actually very proud that I only shot three. The rough was tough and I kept leaving myself in bad spots. I'm glad I'm still on the hunt after a day that didn't feel right. "
Pre-tournament favorite, England's Tom my Fleetwood, is 11 shots behind pace after recovering from playing the first seven holes in three over par to return a 71 and stay three under.
"As much of a round of two cut in half as it was, my putt really kept me from doing a pretty decent round", said the world number 16.