San Jose, Calif.- Reuters Andre Agassi snapped an 18-month winless drought by knocking off old rival Pete Sampras, the world number one, 6-2, 6-4 on Sunday to win the $340,000 Sybase Open. Agassi, in winning this event for a fourth time, claimed his first ATP Tour title since winning the ATP Championships in Cincinnati on August 11, 1996. He earned $45,000 for winning his 35th career singles title. For Agassi, the victory over Sampras provides a major boost to a career that floundered in 1997 when he