"I went to the hole before overtime and he was right there," Allen said of the NBA's second-leading shot blocker last season. I switched it back to my left, he looked like he was about to jump. I knew I had the same opportunity."
Changing his approach near the basket, Allen shot the ball with his left hand to slow Smith for a split second.
"He jumped this time," Allen said. "He was right there at the basket. I just wanted to get the ball up in the air."
Allen finished with a season-high 33 points, 14 coming in the fourth quarter and overtime.
Joe Johnson, who led Atlanta with 28 points, gave the Hawks a 112-111 lead with a runner he banked in from right side with 22 seconds remaining.
"We're trying to come out every game with a lot of energy," Johnson said. "Tonight I thought we got off to such a slow start, which kind of hurt us."
Atlanta had won four straight. Josh Childress forced overtime by tipping in Johnson's missed 3-point attempt with 26 seconds left in regulation.
Rashard Lewis scored 23 and Ridnour 19 for Seattle, which has won two straight on the road for the first time since last Jan. 22-25 at Phoenix and Utah.
Chris Wilcox pulled down 15 of the Sonics' 40 rebounds. The Hawks had 47, led by 10 from Johnson.
Sonics coach Bob Hill wasn't worried when Johnson launched a 3 that fell short from the left wing.
"I've watched people shoot basketballs for so long that I can pretty much tell you that the ball's got a chance or not when it comes out of their hand," Hill said. "I really can, and that one didn't have a chance from the minute it left."
Smith had 24 points for Atlanta, going 9-for-20 from the field and hitting consecutive 3s in overtime. Zaza Pachulia finished with 21.
The Hawks never led by more than five points, the final time coming on Johnson's 13-foot jumper with 7:54 remaining.
Seattle's biggest lead was nine, which Ridnour provided with a pair of free throws early in the third quarter.
The lead changed hands 18 times.
"I actually like close games," Hill said. "I think they're fun. They're more fun when you win. We answered, they answered, and we answered last. It was fun. It was a back-to-back for both teams, so all those guys out there are going to be pretty tired tonight."
Atlanta coach Mike Woodson had a bad feeling as his team continued to struggle with free throws. The Hawks hit just 21 of 33 attempts.
"We came out of training camp shooting 80 percent from the line, and I think we're shooting in the low 70s now," Woodson said. "Over the last few games, we haven't made free throws. I don't know what it is. We just have to go back to practicing and continue to shoot them."
- Johnson became the first player in Hawks history to score 25 or more points in each of the first six games.
- Reserve G Earl Watson, who upset Sonics coach Bob Hill by complaining about playing time the night before, was 1-for-5 from the field with no assists in 19 minutes.
- Lewis recovered quickly after his eye was poked on the last play of regulation. "I went to the basket and I took another dribble and right when I was ready to go for the shot, I got hit in the eye, so I really couldn't see the basket," Lewis said. "I saw that Luke got open at the last second and I flipped the ball to him."