KEY BISCAYNE, Fla. — The WTA Tour is an endless sea of opportunity at the moment. And as each new tournament begins without Serena Williams, the same question arises.

Which player is ready to break away from the field?

Williams, who has a knee injury, has not played since winning the Australian Open in late January, and it is unclear when she will return. But so far this year, with even recent Grand Slam champions faltering, no player has been able to seize the opportunity created by Williams’s absence.

It is against that backdrop that Johanna Konta of Britain stepped up Saturday and defeated the former world No. 1 Caroline Wozniacki, 6-4, 6-3, at the Miami Open, winning the biggest title of her career.

Konta joined the Russian veteran Elena Vesnina — the surprise winner of the BNP Paribas Open in Indian Wells, Calif., two weeks ago — in having triumphed this season on the North American hardcourt circuit.