Full-time caddie Lance Ten Broeck took a one-stroke lead with a second round 68 at the US Senior Open at Lake Orion, Michigan.
Ten Broeck, who carries the bag for Tim Herron on the PGA Tour, made eagle at the par-five 15th to take him to two-under for the day and leapfrog Tom Kite at the top of the leaderboard.
The 56-year-old tied for 71st in his only other outing on the Champions Tour this year and reckons on playing around 25 times a year.
"I figured I should be able to make the cut but I never figured that I'd be in the last group on Saturday," said Ten Broeck, who played 349 times on the PGA Tour without a win.
Kite had to settle for a level par 70 after his opening round of 65, going out in 31 to extend his overnight lead after starting at the 10th hole.
However, the veteran made four bogeys on his back nine to relinquish the advantage at halfway.
"It's a sadistic game, it drives us all crazy," the 62-year-old said after his topsy-turvy round.
"In a championship like this we're all trying to play very well, and they've given us a stern test on a golf course that is very tricky. The greens are very severe in a number of places."
Tom Lehman fired a 66 to sit just two off the lead in a group of six that also includes Bernhard Langer and Corey Pavin, while the round of the day belonged to Jay Don Blake, whose 65 took him to two-under.
The cut came in at +4, meaning Hale Irwin, Eduardo Romero and Kenny Perry will not be around for the weekend.
