WHITE PLAINS, N.Y. -- Elena Delle Donne scored 25 of her 30 points in the first half and the Washington Mystics cruised to a 93-77 win over the New York Liberty on Tuesday night.

Ariel Atkins added 23 points for the Mystics (24-8), who have clinched a top-two seed for the playoffs and extended their lead over second place Connecticut to 1 1/2 games. The season ends Sunday.

Washington raced to a 31-19 lead after one quarter and with Delle Donne scoring 17 points in the second quarter stretched the advantage to 58-40 at the break.

Delle Donne and LaToya Sanders both had 10 rebounds as the Mystics dominated the boards 42-23.

Marine Johannes led the Liberty (9-23), which has lost five straight and 13 of 14, with a career-high 22 points. The rookie from France had scored 21 points in her previous game.

The Mystics, who have won four straight, signed Tianna Hawkins, a former first-round pick, to a contract extension through the 2020 season, then rested her against the Liberty. Kristi Toliver missed her ninth straight game because of a knee injury that is expected to keep her out until the playoffs.