Angel Cabrera, who shared the first-round lead with Stuart Little, posted a 4-under 67. He stands alone in second place at minus-11. Alastair Forsyth fired a 64 to move into a tie for third at 10-under-par 132 along with Darren Clarke and Jonathan Lomas, who each shot 65.
Lafeber played the back nine first at Loch Lomond Golf Club and got off to a hot start. He drained a birdie on the par-3 11th to get to 5 under.
For the second straight round, Lafeber tallied back-to-back birdies from the 13th. He birdied the par-4 18th to make the turn at minus-8.
The 30-year-old birdied the par-5 third for the second day in a row. Lafeber came back with a birdie on the par-5 sixth. He made it two in a row with a birdie on No. 7. The 2003 Dutch Open winner closed with a birdie at the last to cap off a bogey-free round.
'I was doing fine, playing solid all year and stuff, but I felt the mental side of my game was letting me down. I thought that my self-confidence was low and that I was struggling on the course as a result,' said Lafeber, who caught up with his sports psychologist on Wednesday. 'I got positive really quickly and that helped me out yesterday and again today. It's paying off.'
Cabrera played his first eight holes at minus-one after a birdie on the third. He ran in consecutive birdie putts from the ninth to get to minus-10.
The Argentine tripped to a bogey at the par-three 11th. Cabrera converted a birdie on the 13th and made it two straight with a birdie at the next. He closed with four straight pars to take second place.
'I played much better than yesterday, but scored three shots more. That happens in golf,' Cabrera said. 'I only missed one fairway and two greens, but I still think the score is okay. I played really good and had birdie chances on nearly every hole apart from the 18th. However, today was the easiest I've ever seen Loch Lomond, no wind or rain and not like usual at all.'
Gary Orr fired a 6-under 65 in the second round to move to 9-under-par 133. He was joined there by Tim Clark (66), Greg Owen (66) and Richard Sterne (68). Simon Khan and Lee Westwood were one stroke further back in a tie for 10th at minus-8.
Tom Lehman, the 2006 U.S. Ryder Cup captain, is in a group at 7-under-par 135 after a 69. World No. 3 Ernie Els is one stroke further back at minus-6.
Little struggled to a 2-over 73. He slipped into a tie for 31st at 5-under-par 137.
Defending champion Thomas Levet carded a 3-under 68 to make the cut at 3-under-par 139. The cut line fell at minus-2 with 72 players moving on to the weekend.