Sweeting, trailing 5-6 in the second set, saved two set points against his serve as he held on to force the tie-breaker, sealing the victory on his fourth match point.

In other matches at the Houston tournament, Tatsuma Ito won an all-Japanese clash with Go Soeda 6-4, 7-5, the first tour-level meeting between the two compatriots.

Ito booked a second-round clash with fourth-seeded Argentinian Juan Monaco.

Italy’s Paolo Lorenzi set up a meeting with third-seeded Feliciano Lopez of Spain with a 6-7 (3/7), 6-2, 6-3 victory over Wayne Odesnik.

Qualifier Horacio Zeballos booked a marquee second-round clash with America’s Davis Cup hero John Isner via a 6-3, 6-3 victory over Romanian Adrian Unger.

Isner, seeded second in Houston, delivered two singles victories, including the clinching four-set win over Jo-Wilfried Tsonga, in America’s Davis Cup quarter-final victory over France in Monte Carlo at the weekend.

Isner had beaten Swiss great Roger Federer on clay in the United States’ 5-0 first-round Davis Cup whitewash of Switzerland in February.

He has also beaten world number one Novak Djokovic this year, in the semi-finals of the hard-court Indian Wells Masters.

“I’m a much more confident player,” said Isner, who flew in late to Houston and is to open his campaign on Thursday after enjoying a first-round bye.

“To be able to compete in this game you have to be confident, and that’s what I have on my side right now.”

Mardy Fish, ranked ninth in the world, one spot in front of Isner, is the top seed in the $442,500 event.

In the second round Fish will face American Michael Russell, a Houston resident who rallied from a set and a break down for a 2-6, 7-5, 6-1 win over Spain’s Daniel Gimeno-Traver.

In Casablanca, Morocco, Igor Andreev rallied past Denis Istomin of Uzbekistan 6-7 (3), 6-3, 6-2 yesterday to reach the quarterfinals of the Grand Prix Hassan II.

The Russian saved eight of nine break points and broke the fourth-seeded Istomin four times. He will next play Paul-Henri Mathieu of France or Spain’s Guillermo Garcia-Lopez.

Benoit Paire saved 12 of 14 break points en route to a 6-7 (3), 6-3, 6-2 win against Matthias Bachinger of Germany. The Frenchman will meet second-seeded Alexandr Dolgopolov of Ukraine or Flavio Cipolla of Italy.

In Copenhagen, Denmark, fifth-seeded Kaia Kanepi of Estonia defeated Timea Babos of Hungary 7-5, 4-6, 7-6 (2) Wednesday and reached the third round of the e-Boks Open.

Mona Barthel of Germany also advanced to the third round, defeating Alberta Brianti of Italy 6-3, 6-2, while Bojana Jovanovski of Serbia moved into the second round by stopping Stefanie Voegele of Switzerland 6-3, 6-4.