The Phoenix Suns won 104-103 over the Los Angeles Clippers, who had Paul George miss two free-throws, before Ayton’s score from a throw-in.
After George’s double miss on the stripe, Mikal Bridges had missed from an open look to clinch the win but the Suns kept possession with 0.9 seconds left on the clock.
Speaking about the final minute, Suns coach Monty Williams said: “We talk about plays being drawn up and all that, our guys just made plays and stuck with it. When the whistle didn’t go our way, when the ball went out on Book (Devin Booker), I thought we had really good poise.
“Mikal makes a great rebound so we got a time-out. Credit to Jae (Crowder), we were trying to get a lob for DA (Ayton). He had the awareness to just put it up there to where only DA could get it. It’s one of those things that happens, that you just grateful for it.
“I didn’t think we played great tonight but we made enough plays to win the game… It was unreal execution at the end.”
Ayton finished with 24 points and 14 rebounds for Phoenix, while Devin Booker had 20 points, four rebounds and five assists.
But young guard Cameron Payne top scored with 29 points along with nine assists, two steals and two blocks.
For the Clippers, who were missing Kawhi Leonard, George top scored with 26 points, six rebounds and six assists.
Game 3 is in LA on Thursday, with the Clippers needing to come from 2-0 down for the third time this playoffs.