Defending a Grand Slam title is never simple, and Madison Keys felt every bit of that pressure as she opened her Australian Open campaign in Melbourne.

The 30-year-old American returned to the scene of her breakthrough triumph from a year ago, when she enjoyed a dream run that ended with the first major title of her career. This time, the nerves were harder to hide, especially with an unfamiliar opponent across the net.

Keys stumbled out of the blocks on Tuesday, dropping the first four games against Grand Slam newcomer Oleksandra Oliynykova. With little information available on the Ukrainian, preparation had been tricky, and Oliynykova’s patient, defensive style disrupted Keys’ powerful approach.

After a tense first set that went to a tie break, the ninth seed finally found her rhythm. Once settled, she took control of the match, easing through the second set to seal a 7-6 (8-6) 6-1 win and keep her title defence on track.