US Ryder Cup Captain Corey Pavin shot a second successive round of 69 to set the clubhouse target during the second round of The Senior Open Championship presented by MasterCard.
Playing his first Senior Major at Carnoustie, Pavin had recorded four birdies without a dropped shot when he reached the 18th tee, but a hooked five wood second shot landed out of bounds and led to a double bogey six.
But his two under par round took him four under for the week, one shot ahead of Wales' Ian Woosnam and American duo Dan Forsman and Larry Mize in the clubhouse.
"I played pretty solidly today," said Pavin. "Wish I could take that shot over on 18.
"I was pleased with the day - I played well. I had a few times when I put myself in a little bit of trouble, but extricated myself and made some good par putts coming in and a nice birdie on 16.
"It was a good, solid day. Very pleased with two under - I would have taken four under after two rounds, so quite pleased."
Woosnam carded a four under par 67 to go with his opening 72 and the former Masters Tournament winner was delighted to reach the halfway stage under par.
"I'm really pleased with having under par, because I played so poorly this year," said the 2008 Senior Tour Order of Merit winner.
"I've been working hard on my swing, so I don't have any hopes up too much but I'm there or thereabouts and see what happens."
Forsman, already a winner on the Champions Tour in the US this year, added a level par 71, while 1987 Masters Tournament winner Mize had two birdies and a bogey in his round of 70.
On the course, overnight co-leader Bernhard Langer birdied the sixth to move into the outright lead at five under, and American Mark Wiebe birdied the opening hole to join Pavin on four under.
