Uzbekistan's Istomin snapped a three-match losing streak with a 6-3, 7-5 victory over ATP tour newcomer Roman Borvanov of Moldova.

Istomin reached the semifinals in his San Jose debut last year, falling to eventual champion Fernando Verdasco.

Australia's Hewitt advanced with a 6-3, 6-3 victory over Germany's Bjorn Phau.

Former world No.4 James Blake opened his 2011 campaign with a victory, downing qualifier Jesse Levine 7-5, 6-1.

Levine took the first break to go up 5-4, but managed to win just one more game the remainder of the match as Blake converted four of his 11 break point chances.

Blake, who fell out of the top 100 after battling knee and shoulder injuries last season, said he hoped the problems were behind him.

"The main goal right now is to stay healthy and to keep doing everything I need to to keep the body right and then go out there and see how I can perform if I'm healthy," he said.

In other matches, American Donald Young defeated German Dustin Brown 7-6 (7/2), 6-4, Michael Russell edged fellow American Alex Kuznetsov 6-4, 6-2, and wild card Tim Smyczek defeated Colombian Robert Farah 7-5, 3-6, 6-3.

The opening night of the tournament featured an exhibition match in which France's Gael Monfils defeated 14-time Grand Slam champion Pete Sampras 7-6 (7/4), 6-4.

Monfils emerged the winner in a lighthearted contest, taking a camera from a photographer to snap Sampras at one point.

Sampras, 39, was appearing in an exhibition here for the fourth straight year. He displayed his serve-and-volley skills while bantering with the crowd.

In Pattaya, Thailand: Two-time defending champion Vera Zvonareva set out for her third successive Pattaya Open title by beating Tamira Paszek of Austria 6-4, 6-2 in the first round on Tuesday.

The top-seeded Russian, who lost in the Australian Open semifinals to eventual champ Kim Clijsters, came from 3-1 down in the first set. Zvonareva faces Thai qualifier Nungnadda Wannasuk in the second round.

Former No. 1 Ana Ivanovic won the first eight games in beating Thai wild card Nudnida Luangnam 6-0, 6-2 and will next play American veteran Jill Craybas.

Also advancing were No. 4-seeded Daniela Hantuchova of Slovakia, and Nos. 5 and 8 Roberta Vinci and Sara Errani of Italy. However, No. 7 Zheng Jie of China lost to Akgul Amanmuradova of Uzbekistan 6-4, 7-6 (6).

Hantuchova, who arrived in Pattaya a day earlier after a Fed Cup loss in Slovakia, showed no sign of jet lag in her 6-2, 6-1 win over Kurumi Nara of Japan.

She knows what to expect in the second round: Japanese veteran Kimiko Date-Krumm, who eased past Czech player Renata Voracova 6-2, 6-2, has beaten Hantuchova in all three meetings since she came out of retirement in 2009.

Vinci beat Kyrgyzstan qualifier Ksenia Palkina 6-1, 6-3 and Errani defeated Taiwan's Chang Kai-chen 4-6, 6-2, 6-4.

Other first-round winners included Chanelle Scheepers of South Africa, Ayumi Morita of Japan, Elena Baltacha of Britain, and Galina Voskoboeva of Kazakhstan.

In Rotterdam, third seed David Ferrer became the first upset victim at the ATP Rotterdam Open Tuesday as the Spaniard lost 6-3, 6-4 to Finn Jarkko Nieminen in the opening round.

Little more than a week after playing an Australian Open semi-final following his quarterfinal knockout of world No.1 compatriot Rafael Nadal, Ferrer found himself adrift indoors at the Ahoy stadium.

The No. 6 who won his first nine matches of the season, was unable to duplicate his first-round win over Nieminen in Melbourne, exiting in 75 minutes after holding a 3-1 lead in the second set as he attempted a fight back.

Nieminen also won the pair's only other meeting in a Challenger a decade ago. Ferrer produced seven aces but lost serve four times as he went down to his second loss of the season.

The 43rd-ranked Finn, a 2006 semifinalist, will play Serb Viktor Troicki in the second round after improving his modest record this season to 2-3.

The victory was the first for Nieminen in a month since Doha, a victory followed by first-round defeats in Sydney and Melbourne.

Croatian seventh seed Ivan Ljubicic defeated Ukrainian Sergiy Stakhovsky 7-6 (7/3), 6-3 while German Philipp Kohlschreiber lined up as a possible opponent for top seed Robin Soderling after defeating Lu Yen-Hsun of Taiwan 6-4, 7-6 (7/5).

In Costa Do Sauipe, Brazil, Filippo Volandri of Italy beat eighth-seeded Victor Hanescu of Romania 75, 6-1 in the first round of the Brazil Open on Monday.

In other first-round matches in the clay-court event, Ruben Ramirez Hidalgo of Spain defeated Fernando Romboli of Brazil, 6-4, 6-2 and Pablo Andujar of Spain won over countryman Daniel Gimeno-Traver 6-3, 6-1.

Nicolas Almargo is the top-seeded player and fellow Spaniard Albert Montanes is No. 2. Neither played Monday.

Another Spaniard Tommy Robredo, who won the Movistar Open on Sunday in Chile, is seeded sixth.