Tag Ridings, No. 51 on the money list, fired a 6-under-par 65 on Thursday to grab a share of the lead at the season-ending Web.com Tour Championship.
The top 60 players are in the field this week, but only the top 25 on the money list at the tournament's conclusion will earn PGA Tour cards for 2013.
Of the six first-round leaders, only Justin Hicks (11) and Brad Fritsch (21) are in the top 25.
As with Ridings, other Day 1 front runners Michael Putnam (30), Cliff Kresge (38) and Justin Bolli (44) will need to turn in strong performances to earn their PGA cards.
Luke Guthrie, No. 2 on the money list, and Philip Pettitt, Jr. (36) share seventh place at 5-under, while Nicholas Thompson (20), Scott Gardiner (24), Matt Weibring (41) and Edward Loar (44) all carded a 67 on Thursday at blustery TPC Craig Ranch.
Money-list leader Casey Wittenberg is part of a large group tied for 13th at 3-under and No. 3 Russell Henley, who won the Jacksonville Open in a playoff over B.J. Staten last week, is knotted with several others at 1-under.
Also at minus-1 is bubble-watch candidate Doug LaBelle, who resides in 26th place on the money list -- $287 behind No. 25 Camilo Benedetti.
The Columbian Benedetti sits at 1-over.
The Web.com Tour Championship offers the largest purse of the season at $1 million; affording PGA hopefuls a significant opportunity to improve their money-list standings.
First place for the tournament garners $180,000, second place takes home $108,000 and third place earns $68,000.
NOTES: Hicks is the only one of the six leaders to have officially wrapped up a PGA Tour card...Every winner this season on the Web.com Tour is in the field this week. Wittenberg, Guthrie, Henley, Shawn Stefani and Ben Kohles are the only players with two tour wins this season.