Karlsson, who has but one top-10 finish this season, got off to a good start with birdies on six of his first nine holes. Another two birdies on the back, along with one bogey, put him on top of the leaderboard.
Faldo, who went out early and held the lead for most of the day, didn't have a bogey on his scorecard. An eagle at the first saw him off to a great start and he added three more birdies to get to 5-under for the day.
'I am just trying to be very disciplined out there, trying to do what I want to do on each shot,' said Faldo, who needs to move into the top 20 on the European Tour Order of Merit to secure a spot in the World Golf Championships- American Express Championship, which will be played in Ireland in two weeks.
'It's good to feel a bit of pressure, because that is how you learn what to do with your golf swing to make it happen, the key things that have to happen to get the good shots when you want them.'
Faldo, who holds six major titles, came into this event No. 21 on the 2002 Order of Merit.
Lawrie, who won recently at the Celtic Manor Resort Open, actually was in sole possesion of the lead after a six-foot birdie on the 15th moved him to 6-under. But a bogey on the finishing hole cost him the lead and left him in a tie for second with Faldo.
Mathias Gronberg also got it to 5-under late in the day after shooting a pair of 33s that included a eagle-3 at the first hole.
Gronberg, who's best finish was a tie for seventh earlier this year in Dubai, is seeking his fifth European title.
Five players are in a group just two back of the lead at 4-under, and include Spain's Miguel Angel Jimenez, who tied for 10th at last weeks BMW Open.
A large group of eight players sit four off the pace at 2-under-par 69.
British Open champion Ernie Els, who bogeyed both the ninth and 18th hole, is in the clubhouse at 1-under as is fellow South African Retief Goosen. Goosen posted four birdies but gave most of them back with bogeys on the sixth, 12th, and 16th holes.
The father-son combination of Craig and Kevin Stadler saw the newly turned professional Kevin beat his father by a stroke. Kevin, who actually won in his pro debut last week in the Colorado Open, would due well this week just to match his father's result from 2001 European Masters, where the elder Stalder finished in a tie for third.
Denmark's Thomas Bjorn, winner of last week's BMW Open, could manage only two birdies, though no bogeys, for a 2-under-69.
Full-field scores from the Omega European Masters