Lawrence, who held a two-shot lead going into Sunday's final round, opened with three straight bogeys but recovered to shoot a four-under 66 and finish on 22-under for the tournament, prevailing by two shots.
A charging Hojgaard completed the final seven holes in six-under, which included an eagle on the 14th, to shoot the tied-lowest round of the week and he was the clubhouse leader on 20-under after posting an eight-under 62.
But Lawrence birdied the 12th and 14th to regain a two-shot lead and, after parring the final four holes, he repeated his victory in 2022, when he defeated England's Matt Wallace in a play-off.
Defending champion Wallace was in contention again at the Crans-sur-Sierre course, but a bogey at the 14th checked his momentum and a final round of 67 had him tied in second place alongside Hojgaard and Finland's Sami Valimaki.
Another former winner, Matt Fitzpatrick, finished a shot further back after a three-under final round of 67 secured him a fifth-placed finish.
Fitzpatrick had posted two birdies and two bogeys heading into the 15th before birdieing three of the last four holes and his display could be enough to secure him one of captain Luke Donald's picks for the Ryder Cup team.
Jason Scrivener finished as top Australian, a final-round 66 shooting him up to joint-33rd position on nine under.
