England's Carl Mason upstaged both Jack Nicklaus and Tom Watson when he carded a six-under-par 64 to claim a one-shot lead at the end of the second round of the Senior British Open at Turnberry.
Mason was paired with the two American legends for the first two rounds, but left them in the shade.
The former Scottish Open champion returned 67 and 64 for a nine-under-par 131, two shots ahead of Watson and four in front of Nicklaus.
He goes into the third round with a one-shot advantage over DA Weibring and two ahead of Watson, Bruce Summerhays and Tom Kite.
Mason went into today's round one shot behind Watson, but soon showed he was determined to overcome that deficit.
He birdied the 409-yard par-four fourth and the 475-yard seventh on his way to going out in a two-under-par 34 and then picked up four further birdies coming home.
"It was absolutely tremendous out there," said Mason.
"My 61 when I won the 1994 Scottish Open at Gleneagles was special - but, under the circumstances, I would have to say that is probably the finest round I have ever played.
"It was a great honour to play with Jack and Tom. It isn't often you get to play with one legend, far less two. I'm just glad I didn't let myself down.
Weibring was another who made the most of the benign playing conditions.
He opened with a 69, but ended the second round standing on eight-under-par 132 after shooting a scintillating 63 that was just one shot outside Turnberry's Senior British Open record set by South Africa's Harold Henning in 1990.
The 50-year-old American opened his round with three pars, but then birdied the fourth, fifth and seventh to go out in 32.
He carded five further birdies on the 12th, 13th, 14th, 16th and 17th before dropping his only shot of the day when he drove into the rough down the last.
"I got started well and kept it going," said the five-time US PGA Tour winner. "I knew there was a good chance to shoot a good score out there and was able to do it.
"It's just a shame that I finished with a bogey, but that's not going to spoil my day."Ireland's Eamonn Darcy (68) and John McTear (69) also broke par to finish the second round on one over par 141.
PA