Havret, whose last European Tour victory was in Scotland at Loch Lomond last year, had an eagle and four birdies at the five par-5s and finished at 11-under 208. He had a bogey at No. 13 and a double-bogey at No. 15.
Wall (65) birdied seven of the last eight holes, including six in a row from the 11th. Hes one shot ahead of five players ' Marcel Siem (66), Lee Westwood (66), Ricardo Gonzalez (67), David Howell (68) and Soren Hansen (68).
Colin Montgomerie appeared to have lost his chance of a Ryder Cup wild card after shooting a 76, falling into a tie for 54th. Oliver Wilson shot a 68 in an effort to clinch the 10th and final automatic spot in the European team. However, he could be surpassed by Nick Dougherty, who shot a 69.
Captain Nick Faldo will announce the European team on Sunday after the tournament.
I do think I need to win, but it is feasible and it would be a wonderful way to make the team, said Dougherty, who struggled on the greens. Ollys the favorite, but Ill see if I can make him sweat a little.
Wilson was happy to make the cut, with an eagle and two birdies on the last 10 holes Friday.
Montgomerie, who has never lost a singles in his eight Ryder Cup appearances, had little to say after his round.
I think youve got plenty out of me this week, thank you very much, Montgomerie said.
Darren Clarke shot par 73, including a four-putt, double-bogey 7 at the long 12th. Now in 38th place, Clarke must rely on his second victory of the year at the Dutch Open last week to entice Faldo into awarding him a wild card.