Among the action on Tuesday, Americans JJ Wolf and Marcos Giron along with former champion Cristian Garin started their quest to the title defeating their opponents in straight sets.
Kicking off the day, fifth seed Wolf defeated Australian Jordan Thompson (6-3 6-2). The Ohio State All-American is moving on to round two to face fellow American Denis Kudla. This will mark their first ATP match against each other, but are 2-2 in Challenger meetings.
Former champion Garin was victorious in the first round against Bolivian Hugo Dellion, finishing the match in two sets 6-3 6-0. Garin owns five titles and has won 9 out of his 10 matches at River Oaks.
With a history that goes back to their UCLA and USC rivalry, Giron dominated Emilio Gomez, winning the match 6-0 6-2. Giron will face Tomas Machac, who beat American Jack Sock 6-2 6-4.
In a match featuring a pair of qualifiers, Yannick Hanfmann outlasted Yosuke Watanuki in three sets 6-4 3-6 6-2. Hanfmann captured six Challenger titles after playing for University of Southern California, where he helped Trojans win 2 NCAA national titles. Hanfmann takes on second seed Tommy Paul in the second round.
Eighth seed Tomas Martin Etcheverry fights off fellow Argentine Juan Manuel Cerundolo 6-1 6-4. Etcheverry owns 3 Challenger titles all completed on clay. He will go up against either Max Purcell or Daniel Altmaier, who are competing on Wednesday.
In doubles play, 2022 doubles champion, Purcell, with new partner Jordan Thompson defeated wild card Hunter Reese and Reese Stalder 6-1 6-4. Another Australian duo, Rinky Hijikata and Jason Kubler, conquered Americans William Blumberg and Christian Harrison 6-2 7-5.
Closing out Tuesday night, Argentines Facundo Bagnis and Tomas Martin Etcheverry defeated Frances Tiafoe and Dustin Brown 6-2 6-4.
Brandon Nakashima has withdrawn due to a left knee injury. Taking his place is Lucky Loser Zizou Bergs, who will play Garin in the second round.
Main draw action continues at 11 a.m. on Wednesday. Matches will be available to watch on the ESPN App.