Ashleigh Barty insisted she is a worthy world number one on Saturday after defeating Bianca Andreescu to retain her Miami Open crown.

The Australian star, 24, served notice of her determination to be a force this season with a 6-3, 4-0 victory as Andreescu retired with a foot injury in the second set. Barty—who had already been assured of holding on to her No.1 ranking before Saturday’s final—has faced sniping from some players over her continued presence at top spot.