Working primarily from the pocket, Vick went 22 for 31 for a season-high 228 yards. He threw one touchdown pass and had another dropped while directing four drives of more than 70 yards.
"People say I can't throw the ball from the pocket. I had to show them," Vick said. "From here on out, I don't want to hear that question -- if I can throw from the pocket."
The Falcons (6-2) remained tied with Carolina atop the NFC South by converting 11 of 17 third-down situations, totaling a season-high 27 first downs and keeping the ball for more than 36 minutes.
The Dolphins (3-5) went 0 for 9 in third-down situations, including their last one: Keion Carpenter made a diving interception after Miami had reached the 8-yard line with less than three minutes left.
"We're not allowed to be frustrated around here," coach Nick Saban said. "But we're very frustrated."
Vick made several pinpoint throws on the run and scrambled for 38 yards on eight carries. He also looked good in the pocket, threading the needle in several third-down situations.
"I want people to praise me," Vick said. "If I'm winning games, don't criticize me. That's all I'm saying."
Dolphins linebacker Zach Thomas said he couldn't understand the knocks on Vick, who had netted a total of 211 yards passing in the past two games.
"Stats are overrated," Thomas said. "All we talked about all week was Michael Vick -- that tells you how good he is. I don't know why they're so hard on him. He's a heck of a quarterback."
The only possible criticism of Vick and the Falcons would be that they struggled to put the game away. Drives covering 71, 84, 92 and 91 yards produced only 17 points. One threat ended with a fumble and another with a field goal after Brian Finneran dropped a third-down pass from Vick in the end zone.
"We left at least 14 points on the field," coach Jim Mora said.
Poor field position also hurt the Falcons, who started all nine possessions inside their 30-yard line.
Jason Taylor sacked Vick to force a punt from the 5 with seven minutes left, and the Dolphins took over at the Atlanta 42 with a chance to tie. Miami picked up two first downs before Carpenter picked off a Gus Frerotte pass on third-and-2.
"I saw the play develop, and it seemed like it happened in slow motion," Carpenter said.
"I know what everybody's going to say -- 'Why did you throw it?'" Saban said. "We threw it for an interception, so it was a bad play. Just like everyone else, I wish we had done something different."
One final third-down conversion by the Falcons, when Warrick Dunn ran 8 yards on third-and-6, sealed the victory.
The Dolphins' season-long problem with penalties persisted. They had seven for 60 yards, including three false starts.
And Miami gave up a score on the opponents' first series for the seventh consecutive game. Atlanta took the opening kickoff and drove for a score on Dunn's 1-yard run.
Williams' 23-yard touchdown run made it 7-7. Atlanta regained the lead for good when Vick beat a blitz with an 11-yard touchdown pass to Finneran.
"Mike was really good at finding the open spots," Falcons tight end Alge Crumpler said. "When I saw that he threw 31 passes, I was shocked, but what's even more amazing is that he completed 22 of them."
Notes:Falcons RB T.J. Duckett was inactive for the second game in a row. WR Michael Jenkins (ankle) and DE Brady Smith (toe) were also inactive. ... Miami LB Junior Seau returned to the lineup after missing three games with a calf injury. ... Dan Marino gave an emotional speech when honored at halftime for his induction this summer into the NFL Hall of Fame. "It overwhelms you to know that the fans appreciate what you've done, and it makes you want to cry," he said later. ... Marino took part in the pregame coin toss along with former Dolphins Nick Buoniconti, Larry Csonka, Jim Langer and Paul Warfield, all in the Hall of Fame.