Englishman Andy Sullivan shot a second successive 64 to establish an outright lead by three strokes at the Portugal Masters on Friday.
The 29-year-old, who went into the second round with a share of the lead, moved to 14-under-par for the tournament after sinking seven birdies to sit three shots clear of Belgian Thomas Pieters.
Bernd Wiesberger of Austria - who also shot a second-round 64 - and Spaniard Eduardo de la Riva are four strokes off the pace on 10-under heading into the weekend.
English duo Tommy Fleetwood and Anthony Wall are five back, while their compatriots Chris Paisley and Paul Maddy sit in a six-way tie for fifth as it stands.
Saturday's session will see a shotgun start due to the threat of bad weather. It will be only the second time in European Tour history that a round has started that way.
