Vento-Kabchi, ranked a lowly 84th in the world, simply kept the ball in court as Rubin all but beat herself.
Earlier on day one of the $17.1 million Grand Slam, Ashley Harkleroad gave home something to cheer about by racking up her first U.S Open match victory.
The teenager thumped error-prone Russian star Vera Douchevina 6-4, 6-2 in just over an hour.