Bernhard Langer, who has not won on the PGA Tour in eight years, carded a six-under-par 65 to share the first-round lead with Frank Lickliter at the Tour Championship in Houston.
Langer earned a spot in the elite field despite playing in only 16 events.
He finished in the top 10 six times and is 24th on the money list, four spots ahead of Lickliter, who captured his first career win this year at the Kemper Open in May.
World number one Tiger Woods heads a field that was limited to the top 30 money winners on the PGA Tour this season.
However, he experienced a scare when he grabbed his back and winced in pain after his drive off the second tee. Woods, who said he hurt his back on Wednesday, got through his round in one-under 70, leaving him five shots off the pace.
"It the back just acted up yesterday," Woods said. "It's just one of those things. I have to deal with it - try to play the best I can with it."
The already exclusive field is down one to 29 as defending champion and world number two Phil Mickelson is not at the Champions Golf Club following the birth of his second daughter.
Steve Lowery and Scott Verplank are tied for third at 67, one shot ahead of Brad Faxon and Mike Weir.
Six players are tied for seventh at 69, including David Duval, South Africa's Ernie Els and Spain's Sergio Garcia. Among the other top players competing are Vijay Singh of Fiji and Davis Love III.
First round scores from The Tour Championship, Champions Golf Club, Houston, Texas, (US unless stated, par 71)
65B Langer (Ger), F Lickliter
67S Lowery, S Verplank
68B Faxon, M Weir (Can)
69C DiMarco, D Duval, E Els (Rsa), S Garcia (Spa), T Lehman, J Leonard
70S Cink, J Furyk, D Love III, S McCarron, K Perry, V Singh (Fij), H Sutton, T Woods
71M Calcavecchia, B Estes
72B Mayfair
73J Durant, J Sluman, D Toms
74S Hoch, S Stricker
76R Allenby (Aus)