|Portugal Masters third-round leaderboard|
|-19 L Herbert (Aus); -17 T Lewis (Eng); -15 M Kinhult (Swe), E Pepperell (Eng); -14 M Korhonen (Fin), R Paratore (Ita), O Fisher (Eng).|
|Selected others: -12 A Sullivan (Eng); -11 M Wallace (Eng), J Smith (Eng).|
England's Tom Lewis moved into contention for his first European Tour win since 2011 after a 10-under-par third round at the Portugal Masters left the former champion two shots behind Australia's Lucas Herbert.
Lewis fired 10 birdies in a bogey-free round of 61 to move to 17 under.
Leader Herbert dropped his first shot of the week in a seven-under 64.
Sweden's Marcus Kinhult and England's Eddie Pepperell sit tied for third, four shots off the pace.
England's Oliver Fisher followed his record-breaking second round of 12-under 59 with a third round of two-under 69 to drop into a tie for fifth with Finland's Mikko Korhonen and Italy's Renato Paratore at the Dom Pedro Victoria Golf Course in Vilamoura.
World number 184 Lewis, 27, won his sole European Tour title at the 2011 Portugal Masters before winning the Bridgestone Challenge on the second-tier Challenge Tour earlier this month.
He also finished tied for third at last week's Kazakhstan Open, also on the Challenge Tour.
World number 158 Herbert, 22, is seeking his first win as a professional.
"I got hot with the putter pretty early, but I probably stalled a bit on the back nine," the Australian told Sky Sports.
"I was pretty happy to finish at seven under, although I would have liked a few more coming in."