The eight-time European Tour Order of Merit winner played an unblemished 17 holes before failing to get up and down from in front of the green at the par-four last to finish a fine first day with a four-under-par 68, one shot shy of Argentina's Luis Carbonetti, the 2004 Senior Masters Champion.
Also at four under was the South African Steve van Vuuren, while the trio of former Ryder Cup captain Mark James, Ireland's Philip Walton and Englishman Andrew Sherborne all signed off with three-under-par 69s for a share of fourth.
Montgomerie, billed as the star attraction in his third Senior Tour appearance, did not disappoint, with four birdies in his first six holes to reach the turn in 33. Driving superbly all day, a fifth gain followed at the 10th to send Montgomerie top alongside morning starter Carbonetti, but seven straight pars preceded an unlucky conclusion as he bogeyed the last.
"You don't win here in the first round, just get into a good position to move forward and that's what I've done so all-in-all I'm satisfied," said the Scot. "It is a golf course that suits my eye. I hit most fairways and if you do that then you usually score well."
Carbonetti, who won this tournament in 2004, negated chilly early conditions with some accurate striking of his own to sign for a five-under 67.
Like Montgomerie, the 60-year-old missed only one fairway - at the 16th where he made his one and only bogey - while his five birdies came from within 10 feet but defending champion Des Smyth, looking to complete a hat trick of wins this week, struggled to find his best in a one-over 73.