Bernhard Langer birdied three of his opening nine holes to edge clear at the top, but a flying David Frost was close behind during the third round of The Senior Open Championship Presented by Rolex.
Langer, who held a share of the lead with American Mark Wiebe overnight, was playing beautifully as the afternoon progressed at Royal Birkdale Golf Club, birdieing the third before two in a row from the difficult sixth saw the German reach eight under par through the turn.
The 2010 Senior Open Champion was briefly three shots clear of the field after Wiebe went backwards, but a hat-trick of birdies from the seventh saw South African David Frost also turn in 31 to stay within one of the lead.
Peter Fowler was next best in more pleasant conditions on Saturday afternoon in Southport, as the big Australian bounced back from a bogey start with successive gains at the following two holes to get to four under par alongside Wiebe.
Despite plenty of sunshine on the north west coast of England, Birkdale was again showing its teeth during the third round with only Langer and Frost bogey-free so far today and just six players left under par for the tournament as the day wore on.
Englishman Gary Wolstenholme was another going nicely on Moving Day, birdieing four out of six holes from the 12th to get back level par for the tournament – eight shots off the lead.
Earlier, Spaniard Miguel Angel Martin matched the low-round of the week, carding six birdies en route to a superb 65. Having made the cut by one stroke, Martin was well inside the top 15 on two over par as play continued at Birkdale.