England's Matt Wallace was two strokes behind leader Cameron Tringale after the American shot a three-under 69 on the second day of the Valero Texas Open, while Padraig Harrington and Graeme McDowell made the cut.
Starting on the back nine, Tringale had a poor beginning when he bogeyed the 10th and 11th before improving to make five consecutive birdies from the 13th to the 17th and finished with an overall score of nine-under 135.
Wallace, looking for his first PGA Tour title after four wins on the European Tour since 2017, had a bogey-free round and collected four birdies to card a 68 to go with his 69 the previous day.
Former champion Jordan Spieth shot 70 to finish the day tied second with Wallace on an overall score of 137, while first-round leader Camilo Villegas's 76 saw him fall five shots back from Tringale.
European Ryder Cup captain Harrington of Ireland carded a 74 to be nine strokes off the pace in a share of 32nd place, one shot clear of McDowell who posted one under in his second round.
Previous tournament winner Martin Laird of Scotland another shot back in a group which included England's Tom Lewis.
Scot Russell Knox missed the cut after carding 73 and was joined by the 74-shooting Englishmen Danny Willett and Luke Donald.