American Kirk Triplett and Thailand's Thaworn Wiratchant have both shot seven under 65 to lead the Senior British Open by one stroke after the opening round but both will be keeping a close eye on defending champion Bernhard Langer.
Meanwhile, Australian Paul Archbold is four shots off the pace after shooting an error-free three under par 69 St Andrews on Thursday.
Long the dominant figure in over-50s golf, Langer arrived as the man to beat on. And not much has changed.
While Langer's five under 67 wasn't the best score over the Old Course, the German's lofty presence on the leaderboard will have the attention of every other contender.
Langer is tied for fifth alongside former PGA champion David Toms and another American, Scott McCarron, with the trio one shot behind former Ryder Cup captain Paul McGinley and Canadian Stephen Ames.
As many as 16 players shot 68 or less, a figure that almost included 68-year old Tom Watson, on a bright and breezy day.
The seven men atop the leaderboard were all at least 3-under par by the turn. But it was a different matter coming home. No one in the 144-strong field was better than 3 under for their final nine holes.
Wiratchant's round was highlighted by a run of five straight birdies from the third hole. Four more followed, with dropped shots at holes 13 and 17.
Australian David McKenzie finished two under par on equal 27th on the congested leaderboard.
The Victorian birdied three on the front nine and one at the start of the back nine, then bogeyed two, before recovering with a birdie on the 18th.
Countryman Peter Fowler had a forgettable round, carding four birdies and three bogeys, to end just one under par.
