A jittery Madison Keys admitted on Tuesday that she was “too timid” after getting the defence of her Australian Open crown off to a stuttering start, losing the first four games before rallying to stay in the title hunt.

The American World No. 9 was a bundle of nerves on Rod Laver Arena, but calmed down to clinch a 7-6 (8-6), 6-1 win over Ukraine’s Oleksandra Oliynykova.