Afterward, coach Andy Reid said Vick suffered a concussion. Vick was to fly home with the team, but it appears he will miss Sunday's home opener against the Giants and that backup Mike Kafka might have played his way into a starting job while Vick recovers.
While, to a man the Eagles were impressed with Kafka's performance, they recognize Vick's value.
"Talent like that - you do not replace it," said running back LeSean McCoy. "We've got to protect Mike better. I've got to protect Mike better."
On the drive before that one, Maclin absorbed a helmet to the chin from headhunter cornerback Dunta Robinson, who dealt DeSean Jackson a concussion last year on a similar play. Maclin looked like he was destroyed . . . but he returned two plays later. He had already caught two TDs.
"Now he's 2-for-2," Maclin said of Robinson. "I was all right. It almost shocked me."
He later snared a 43-yard bomb from Kafka, the only other quarterback on the Eagles' active roster. Vince Young was inactive, still nursing a preseason hamstring injury. Maclin finished with 13 catches, 171 yards and immeasurable respect from his teammates.
That bomb took the Eagles into Falcons' territory with just under 4 minutes to play, a crisp drive engineered by Kafka in his first regular-season playing time since he was drafted in the fourth round last year.
It was Kafka's finest hour. The drive died with 1:41 to play when Maclin dropped Kafka's fourth-and-4 pass from the Atlanta 22 in the middle of the field.
"I'm better than that," Maclin said.
Vick was often scintillating, but he was far from perfect.
He fumbled twice, one of which led to a touchdown, and threw an interception that also led to a touchdown. He was not sacked.
But he was battered. Ultimately, he was knocked from the game. Kafka took over that drive, absorbed a roughing-the-passer penalty and handed off to McCoy, who rushed for a 4-yard score to give the Eagles a 31-21 lead late in the third quarter. That matched the 8-yarder that gave the Birds the lead earlier in the third.
McCoy had 95 yards on 18 carries.
Amid the succulent distraction of Vick's return to Atlanta, what took place in the House That Mike Built mattered even more. The Eagles needed to find out if Vick and the reconfigured offensive line could produce without significant error against a real defense, after a sputtering, season-opening win in St. Louis. They also needed to know if their defensive weaknesses up the middle could survive a full game being challenged by a top running back.
All of those questions were answered: No, No, and No.
Did it matter?
It mattered a lot.
The defense had no answer for tight end Tony Gonzalez, who snagged two touchdown passes, one over safety Kurt Coleman, the other over linebacker Jamar Chaney, and had seven catches for 83 yards.
It bellied up in the face of bully back Michael Turner, who rolled for 114 yards on 21 carries, including a gutting, 61-yarder midway through the fourth quarter that set up his go-ahead TD run with 4:48 left. He ran through Chaney and past unwilling corner Asante Samuel.
Cornerback Nnamdi Asomugha, when asked if the Eagles must shut down an opponent in such a late-game situation to establish an identity, said, "One hundred percent, that's right. It doesn't matter how good you play in the first three quarters. If you can't finish strong you're not there yet."
Referring to Turner, linebacker Moise Fokou said, "Somebody didn't have the gap. Him gashing us like that in the fourth quarter really hurt us."
Rookie middle linebacker Casey Matthews said, "It was people out of position on that last drive. We didn't lower the safeties down."
The defense also intercepted Penn Charter product Matt Ryan twice and sacked him four times. They were pretty picks by big-money corners Nnamdi Asomugha and Samuel. But it could not win basic battles.
"This teaches us you can't just rely on your offense, on a lot of playmakers to make plays and win the game for you," Fokou said.
The offensive line might be porous, but with speed in the form of Vick, Jackson, Maclin and LeSean McCoy, such deficiencies can be overcome . . . against the likes of the Rams.
Not against a team that hits and runs like Atlanta.
Ryan finished with a career-best four touchdown passes and was 17-for-28 for 195 yards, but he was almost coincidental on the winning drive.
Which is fine by him.
Ryan entered with Tony Romo-like baggage; a first-round playoff loss last season, then a season-opening loss at Chicago.
Vick, of course, entered with a mountain of luggage.
Vick first took the field in a T-shirt and shorts just after 6:30 p.m. to scattered cheers from a few dozen who, perhaps, remain fans after his fall from grace in Atlanta. At about the same time, at least one publicity hound in the parking lot burned a Vick jersey - an unoriginal pastime in Atlanta since Vick's graceless fall.
Vick, the No. 1 pick in the 2001 draft, played for the Falcons for six seasons before a dogfighting conviction cost him the 2007 and 2008 seasons.
The Eagles signed him out of prison, made him a backup and Wildcat specialist for 2009 and brought him home late that season. He ran for a touchdown and threw for another in support of starter Donovan McNabb. With McNabb gone to Washington, Vick had won the Eagles' starting job from Kevin Kolb last year when Atlanta visited Philadelphia, but he missed the game with torn rib cartilage and did not take the field.
Last night, he threw a few passes, hugged Ryan, then hugged Falcons owner Arthur Blank, to whom he lied during the investigation that sent him to prison, and to whom he owed about $7 million after defaulting on his contract with the Falcons.
Vick took the field a second time in full uniform just past 7:30 p.m., this time with the Georgia Dome half full . . . and this time to a cascade of boos that drowned out any cheers.
When he finally took the field for real, at 8:31, the dome was full and almost fully derisive.
Its mood waxed and waned as the game progressed, but as the Eagles churned from a 21-10 deficit to a 31-21 lead, Vick got plenty of love.
How would he have been regaled, or reviled, at the game's end?
If he had won?
We'll never know.
Defensive end Juqua Parker left the game in the fourth quarter with an ankle injury and did not return . . . Wide receiver DeSean Jackson played through a buttocks strain that intermittently cost him playing time during the game . . . It was Jeremy Maclin's fifth multiple-touchdown game in just 33 games.