The Englishman carded a second successive 66, with birdies at the first, the 11th and four of the last six holes to eventually move ahead of a developing logjam at the top of the leaderboard.
France's Gregory Bourdy shot 64 to leap to 11 under alongside Scot Marc Warren and Spaniard Gonzalo Fernandez-Castano, who both went round in 65, and Garth Mulroy of South Africa (67).
Bourdy said: "This morning [Friday] it was perfect conditions to play on this course.
"It was a lovely round and I enjoyed it a lot. I was very solid and I'm very proud. Almost everything went right today [Friday].
"Last week my driving was wonderful and so were my irons, and that continued today [Friday]. I'll try to do the same at the weekend."
Richard McEvoy was at 10 under after following his opening 66 with a four-under-par 68.
First-round leader Joel Sjoholm fell into a seven-way tie for seventh on nine under after failing to go with the trend of improved scoring on Friday.
He could only follow Thursday's eight-under-par 64 with a 71 and was level with fellow Swedes Mikael Lundberg and Joakim Lagergren, Spain's Pablo Larrazabal, South African Richard Sterne, England's Sam Little and Victor Dubuisson of France.
English pair Lee Slattery and David Howell were hot on Sjoholm's tail overnight and that was where they remained, shooting 71 and 70 respectively to join compatriot Robert Coles and a host of others on eight under.
Ryder Cup-bound Martin Kaymer, Spaniard Rafa Cabrera-Bello, Welshman Bradley Dredge, Darren Fichardt of South Africa and India's Shiv Kapur completed the group.
A second Ryder Cup player, Italian Francesco Molinari, was in the group at seven under as was Graeme Storm, who was fifth in Holland last week having led for two rounds and started well again here with rounds of 69 and 68.
Molinari's brother Eduardo, the big-hitting Alvaro Quiros and Frenchman Thomas Levet were among the higher-profile players to miss the cut.