Stewart made 9 of 12 from the field, grabbed eight rebounds and had three steals. Natasha Howard added 13 points and Sue Bird had 11 assists for Seattle. The Storm (13-5) moved into a tie with Phoenix atop the WNBA standings.
Stewart made back-to-back baskets to spark a 14-0 run that gave Seattle an 11-point lead when Bird hit two free throws with 32.1 seconds left in the first half. Epiphanny Prince answered with two foul shots, but Loyd's putback of an airball by Howard at the buzzer made it 39-28 at the break and the Liberty trailed by double figures the rest of the way.
Bria Hartley led New York with 16 points. The Liberty (5-12) have lost six of their last seven games.
The Storm had 25 assists on 30 field goals.