"I thought it was going to be 120 or something the way it was in the first half," Suns coach Terry Porter said of the game which Phoenix led 59-58 at halftime. "There wasn't that much defense to be played in the first half. It was like we had signed a peace treaty with each other."
Raja Bell scored 18 points and Boris Diaw added 15 points for Phoenix.
Steve Nash scored 11 points before leaving with a sprained right ankle with a little more than two minutes left in the first half. He may be held out of Friday's game against the Nuggets at Syracuse, N.Y., as a precaution, according to Suns spokeswoman Julie Fie.
Hawks second-year point guard Acie Law hit two free throws with 26.6 seconds left to tie the game at 100. Law, starting his third consecutive game in place of Mike Bibby, had six assists and 12 points.
Following Hill's go-ahead jump shot, Law's last-second layup was blocked by Louis Admundson.
"I'm glad Louis blocked that so we could go to the airport," Hill said.
Hawks coach Mike Woodson said Law "had a great play at the rim, but (Admundson) made a great stop."
Flip Murray led the Hawks with 23 points, including 15 in the first half. Al Horford, starting at forward, had 15 points and six rebounds. Zaza Pachulia, starting at center, had seven points and 10 rebounds.
"We didn't defend like we could have," Horford said. "We gave up a lot of layups, stuff like that. It's things we need to clean it up before the regular season starts. ... Guys were coming in and shooting the ball quickly rather than running offense."
Suns center Shaquille O'Neal was in street clothes, getting the night off while coach Terry Porter looked at some smaller lineups.
Rookie Robin Lopez, the 15th overall pick in this year's draft, had nine points and nine rebounds starting for O'Neal.
Hill added 13 points and rookie Sean Singletary scored 13 points.
F Amare Stoudemire (torn iris in right eye) and Leandro Barbosa, who returned to the team this week after being with his ailing mother in Sao Paulo, Brazil, also did not play for the Suns. ... Hawks coach Mike Woodson gave Bibby (strained right oblique) the night off. ... G Mario West left the game with a sprained left ankle. ... PG Speedy Claxton has missed all five preseason games with a pulled hamstring.