Two more Scots, Gary Orr and Steven O'Hara, shared the lead along with Paul Broadhurst, Brett Rumford, Ricardo Gonzalez, Soren Kjeldsen, Steve Alker and Jose Manuel Lara.
Lawrie has struggled with his putting this year, missing the cuts at his three previous events, but has switched to a new putter.
'I holed some 8-10 footers today which I haven't been making,' said Lawrie, who won the 1999 British Open in a playoff when Jean Van de Velde threw it away on the final hole.
A group of 13 players on 66 included 2005 U.S. Open champion Michael Campbell and Welsh hope Bradley Dredge.
Two-time U.S. Open champion Retief Goosen birdied his last hole for a 1-over 70.
He felt he has not played well since the weekend of the Masters in April, when he finished tied for second.
'I want to get play-fit. At the moment it's a struggle and I'm waiting for it to start happening,' Goosen said. 'Every time I hit a good shot today, it was the wrong club.'
editor's note: The GOLF CHANNEL will have coverage off all four rounds beginning at 10:00 a.m. ET on the first two days and 9:00 a.m. on the weekend. Next week is the BA-CA Golf Open, where Markus Brier won last year.