Ross Fisher and Robert Karlsson both had disappointing days in the fourth round of the PGA Tour Qualifying Tournament at La Quinta in California.
The European duo are both hoping to secure a top-25 placing in the six-round tournament which would secure a PGA Tour card for 2013.
Sweden's Karlsson was second at the start of the day but recorded two double bogeys on his way to a three-over 75, leaving him in a share of 17th place overall.
Englishman Fisher fired a level-par 72 and is one shot behind Karlsson in a tie for 20th place on 13 under.
South Korean Lee Dong-hwan sets the pace on 19-under 269 after shooting a flawless eight-under 64 which contained eight birdies.
His compatriot Kim Meen-whee (73), who led after three rounds, is two shots back in a tie for second with American trio Edward Loar (71), Vaughn Taylor (70) and Richard H Lee (64).