Mark Calcavecchia keeps share of lead
Calcavecchia -- one of three overnight leaders -- made six birdies in his 3-under 69. He was joined at 7 under by Rinker and Canada's Rod Spittle, who each shot 67 at Walton Heath.
It's the first time since 2004 that at least three players have held a share of the lead after 36 holes of a Senior British Open.
Senior British Open Leaderboard
T-1. Calcavecchia (-7)
T-1. Spittle (-7)
T-1. Rinker (-7)
4. Fowler (-5)
T-5. Cook (-4)
T-5. Goodes (-4)
Australian Peter Fowler was two shots back after a 68, with American pair John Cook (67) and Mike Goodes (70) tied at 4 under. Defending champion Bernhard Langer faded with a 76, nine shots off the pace.
Fowler, a two-time winner on the Senior European Tour this season, holed a pitch shot for birdie on No. 16. England's Kevin Spurgeon had the low round with eight birdies for a 66.
Tom Watson had a bogey-free 68 to move into contention at 1 under, along with Mark O'Meara and Tom Lehman, who each had a 72. Americans filled six of the top nine places, improving the likelihood of an eighth U.S. winner in nine years.
Calcavecchia and Rinker live near each other in Jupiter, Fla., and grew up playing junior golf together. However, their careers have taken different paths.
While the 50-year-old Rinker doesn't have a career victory, Calcavecchia is best known for winning the British Open at Troon in 1989 and has 12 more wins on the PGA Tour.
"That would be awesome company to keep. They're three Hall of Famers. That would be really special," Calcavecchia said.
Rinker, in his first season on the Champions Tour, only sealed his spot at Walton Heath with a top-10 finish last month at Endicott, N.Y. He had five birdies in a blemish-free round.
"It's been a long time since I've been in this position," said Rinker, whose best showings were two second places in 1997. "But my game's been coming along this year. We'll see how I hold up."
Spittle joined the American pair atop the leaderboard toward the end of the round, finishing with six birdies in the last 10 holes.
Langer had a double bogey on the par-4 No. 4, adding to three other dropped shots.
Copyright 2011 by The Associated Press