The biggest tennis title of Leylah Fernandez’s career arrived at the D.C. Open with the help of a terrific backhand, some superb returning — and energy courtesy of Shake Shack’s burgers and fries.

Fernandez, the runner-up at the 2021 U.S. Open, hit 12 aces and picked up her second victory of the week against a top-20 opponent by beating 2022 Wimbledon champion Elena Rybakina 6-7 (2), 7-6 (3), ...