Ramsay produced the only bogey-free round on day three, carding a seven-under-par 64 to move to the top of the leaderboard.
It was one stroke clear of Lawrie, who drove out of bounds at the 14th en route to a 67 for a 10-under total on the Crans-sur-Sierre course.
The Scots will be out in the last group, with Ramsay looking for only his second win on Tour after success in the 2010 South African Open.
Lawrie is just as determined to capture a third win this season, a week after capturing the Johnnie Walker Championship.
He had been forced to wait on the 14th tee for some minutes due to slow play, then stepped up to drive and set up a double bogey.
"I played lovely out there but just missed so many putts," said Lawrie. "Then you hit one poor shot and you make double bogey, but that's golf, as you are not going to make them all. So my assessment is that it could have been four or five shots better."
Ramsay heads into the last day looking to celebrate his forthcoming marriage on the weekend of the Ryder Cup.
"A win tomorrow ahead of my wedding would be fabulous but then everyone will be expecting a free bar," he said, laughing. "It would be unbelievable if I could win as there are a lot of people who have helped me over the last two to three years, so that would be good reward for them, as well.
"I feel as though I have come so far after winning in South Africa and a win would be brilliant.
"It's nice also that Paul is up there in second place as I know him so well. It's going to be like two Aberdonians trying to knock each other off first place but then my goal is to play my own game and that will be vital."
Ramsay picked up birdies in three of his opening five holes before adding three more on the back nine.
Lawrie had looked on course to top the leaderboard heading into the final day after climbing to first place on the back of an eventful start to his third round, which included an eagle three on the first. Following that he picked up four birdies, while dropping shots at the third and fifth, to reach the turn in 31 before adding another birdie at the 12th to move to 12 under. However, after the 14th he could not pick up any more shots and he finished with four pars.
Danny Willett, meanwhile, followed up his back-to-back 67s with a 68 to be joint second. He started with an eagle at the first but dropped shots at the second, 13th and 16th threatened to leave him further down the leaderboard before he finished with successive birdies.