Third-seeded Serena Williams clawed out a 7-6 (8/6), 3-6, 7-6 (7/0) victory over hard-hitting Dutch qualifier Arantxa Rus on Monday to avoid joining the WTA upsets at the Western & Southern Open.
The 23-time Grand Slam champion, currently ranked ninth in the world, fired 14 aces in the hard-fought victory that lasted two hours and 49 minutes on the Grandstand court at the National Tennis Center in New York.
She advanced to a third-round clash with either Maria Sakkari of Greece or Kazakhstan's Yulia Putintseva.
Williams won this tournament, usually held in Cincinnati, in 2014 and 2015.
With the event being held this year in New York in the same quarantine bubble that will house the US Open starting on August 31, Williams is the highest remaining seed in the women's draw.
Top-seeded Karolina Pliskova and No. 2 Sonia Kenin both lost their opening matches on Sunday.