New York (11-5) is off to its best start since going 16-5 in 2001.
Tanisha Wright added 12 points for New York, including a fast-break layup with 36 seconds left for a three-point lead. Swin Cash scored six points to move past Sheryl Swoopes for 14th place on the league's all-time scoring list.
Sue Bird and Ramu Tokashiki scored 14 points apiece for Seattle (5-13), which lost to New York for a fifth straight time. Seattle begins a six-game road trip after the All-Star break, returning to the KeyArena on August 14.
Seattle fell behind 26-13 after the first quarter, hitting just 28 percent (4 of 15) from the field. But the Storm outscored the Liberty 32-14 in the second, closing on a 10-2 run with 3-pointers by Bird and Alysha Clark, for a 45-40 lead.