Sancho Lyttle's three-pointer with 12.2 seconds 88 victory over the Connecticut Sun.
Lyttle finished with 20 points -- four in the extra period -- and Angel McCoughtry added 26 points and 12 rebounds as the Dream won their third straight contest.
Erika de Souza added a double-double of her own with 12 points and 10 boards, and Lindsey Harding poured in 21 for Atlanta.
Asjha Jones paced the Sun with 21 points. Tina Charles scored 15 and pulled down 11 rebounds as Connecticut dropped its second consecutive contest.
After Jones' jumper put the Sun up 78-75 with under three minutes to play in the fourth, each team traded turnovers and missed shots until Lyttle threw up a shot from beyond the arc as time was winding down. The shot hit the front of the rim, bounced up and hit the backboard before falling in for the tie.
Connecticut had a chance for a buzzer-beater as time ran out when Allison Hightower set up for a three in the corner. But McCoughtry made a tremendous block on the shot, sending the game into overtime.
The Dream made three of the first four shots in overtime to take a four-point lead, but Jones' jumper and ensuing foul shot made the score 84-83.
McCoughtry then made consecutive shots to put Connecticut up by five, and Lyttle's free throws after a Tan White three put the Sun within two before foul shots by Lyttle and McCoughtry iced the win.