Local favorite John Isner crashes out (photo: tenniscourtsmap.com)

The U.S. Men’s Clay Court Championship in Houston will be devoid of some of its seeds, who faced stunning second-round defeats from the hands of their respective counterparts on Thursday.

2^nd seed Roberto Bautista Agut was a no match for local hope Jack Sock, who exhibited a spectacular piece of tennis to pull off a 6-4 6-4 triumph.

No. 4 seed and local favorite John Isner also got trapped by the upset bug, as 79^th-ranked Teymuraz Gabashvili clinched a 6-2 7-6 conquest of his lanky counterpart.

Serbia’s Janko Tipsarevic, who was making his return on the tour after 17 months, also crashed out of the tournament following a 7-6 6-3 loss to 5^th seed Santiago Giraldo.

2^nd Round Results

T Gabashvili d. (4) J Isner 6-2 7-6

(6) F Verdasco d. (Q) H Chung 7-6 6-2

(5) S Giraldo d. (W) J Tipsarevic 7-6 6-3

J Sock d. (2) RB Agut 6-4 6-4