Tennys Sandgren cruised through in straight sets against Blaz Kavcic to secure his first main-draw victory in the US Men's Clay Court Championships on Monday, but fellow seed Fernando Verdasco fell at the first hurdle.

Verdasco, the fifth seed, won the tournament in 2014 but was knocked out in the first round for the first time, Denis Kudla claiming a hard-fought 6-4 7-6 (7-4) win.

Kudla, the world number 122, was playing on clay for the first time since 2016 but proved too strong for Verdasco, recovering from 4-1 down in the second set to progress following a tie-break.

A 6-2 6-2 victory for eighth seed Sandgren against Kavcic in Houston means the American will face either Nicolas Kicker or Donald Young in the second round.

Wild card entry Dustin Brown was dumped out by Henri Laaksonen, the 26-year-old progressing impressively thanks to a 6-4 6-3 success.

Laaksonen will meet the event's top seed John Isner - winner of the Miami Open last week - as a reward for his victory.

Jordan Thompson suffered a heavy 6-1 6-1 defeat at the hands of home hope Bjorn Fratangelo, who next takes on another Australian, the fourth seed Nick Krygios.

In the last match of the day, 20-year-old Frances Tiafoe beat fellow American Mackenzie McDonald 6-3 6-3 to set up a possible second-round clash with defending champion Steve Johnson.