Ilya Sorokin made 26 saves for New York (9-6-0), which had won two straight.
"You can't score if you don't hit the net," Islanders coach Lane Lambert said. "(That's) the bottom line. Seventeen attempts blocked and 23 missed nets or missed shots. That's too many."
Boyd gave the Coyotes a 1-0 lead at 1:00 of the third, redirecting in a cross-crease pass from Clayton Keller near the right post.
"Keller and I have some pretty good chemistry, and we were talking about it (going) into the third, about what he was seeing, what I'm seeing, and yeah, (it was) just a little variation of what we usually do," Boyd said. "He kind of started walking down, so (I) just kind of fell off to that backside and he was able to put it on my tape, and I was able to direct it in."