The Scot, bidding for his fourth Senior Major Championship and first on British soil, completed 12 holes before the suspension, twice leading outright on six under par before bogeys on the tenth and 12th holes, either side of a birdie on the 11th, pushed him back to five under par, alongside seven other players.
With constant rainfall throughout the morning, play was suspended at 1pm with the greens on the Old Course waterlogged. Further heavy rain after the suspension, and a worsening forecast, meant the decision was then taken at 3pm that the players would not return to the course, with 16mm of rainfall already measured at that point.
It means the second round will resume at 8am on Saturday morning, followed by a two-tee start for round three upon its conclusion.
Montgomerie will have six holes to complete when the play resumes on Saturday, having moved up the leaderboard to join the cluster of pacesetters.
Seven other players also lie on five under par, including defending champion Bernhard Langer and Spaniard Miguel Angel JimÃƒÂ©nez, though only one of them, American Bart Bryant, has started his second round, parring the first two holes before the rain made the saturated greens unplayable.
The leading Australian is Peter O'Malley who after an opening round of 68 has yet to begin round two as are Peter Senior and Peter Fowler who are one shot behind O'Malley after opening rounds of 69.
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