Updated

Third-seeded Feliciano Lopez of Spain had four of his 13 aces in a tiebreaker to overpower Italy's Paolo Lorenzi 6-4, 7-6 (4) on Wednesday night in the second round of the U.S. Men's Clay Court Championships at River Oaks Country Club.

Lopez, ranked No. 15 in the world, played on clay for the first time this year and fell behind 4-1 in the opening set before unleashing his big serve to pull out the set. Lopez had three aces to take a 6-1 lead in the tiebreaker and closed it out with an ace at the fourth match point.

Top-seeded Mardy Fish, ranked No. 9 in the world, and second-seeded John Isner, No. 10, will play their first matches Thursday. They had first-round byes.

Fifth-seeded Kevin Anderson of South Africa got control of his serve in the second set and beat Brazil's Joao Souza 6-3, 6-4 in a first-round match.

The match started with four straight service breaks before Anderson held in the fifth game. He broke Souza again in the eighth game and served a love game to win the first set.

Anderson had four double-faults and Souza had three in the first five games.

Anderson broke Souza in the 16-point ninth game of the second set for a 5-4 lead. Anderson fell behind 15-30 while serving for the match. He then hit two aces and won at the first match point with a volley winner.

Ryan Harrison of the United States boomed 13 aces, including the final two points of the match at 130 and 133 mph, to upset seventh-seeded Alex Bogomolov Jr. of Russia, 4-6, 6-3, 6-4 in the first round.

Harrison, ranked No. 65 in the world, overcame three break points in the fourth game of the final set to hold and then broke the Russian in the fifth game for a 4-1 lead.

Bogomolov broke back in the sixth game, but Harrison won it at the first match point. Harrison saved nine of 11 break points in the 2-hour, 18-minute match.