The Ryder Cup winner takes the slenderest of advantages into the third day, with Martin Kaymer a shot behind.
Four players then trail on one under; Bill Haas, Francesco Molinari, Louis Oosthuizen and Charl Schwartzel, with two-time defending champion Lee Westwood on level par.
Behind him is Peter Hanson (one over), before a real gap to the rest, with Carl Pettersson three over, Nicolas Colsaerts and Garth Mulroy four over and finally, Justin Rose, a further four shots back.
Friday was a horror day for the Englishman, a seven-over 79 not amongst his finest rounds, but Lawrie will at least sleep easy tonight after his 69.
He could have signed for an even better score too, with a bogey on the 15th-hole par four stopping him from registering the outright best round of the day.
Kaymer also carded a 69 consisting of five birdies and two bogeys, while Westwood, looking for a third successive win at the event, was left to rue a bogey and a double-bogey six at the par-four 16th as he ended one over for the day.
He had little on compatriot Rose, though, whose score was heavily undermined by a triple bogey on the par-four third.