And Myles Garrett came up with another big defensive play for the No. 14 Aggies, even though they still needed overtime again to beat Arkansas.
Allen threw for 358 yards and two touchdowns to Kirk, the second a 20-yarder in overtime as Texas A&M won 28-21 in the SEC opener Saturday night in the home of one of the Razorbacks' most notable alums.
"I saw a lot of guys focused," Allen said, noting what he saw while on the bench late in the game with the defense on the field. "Not like crazy energy, but we were focused, and I knew that when I saw that, I was confident we could go out and make plays."
Garrett, the national sacks leader, was held without a sack until just over a minute left in regulation, when he wrapped up Brandon Allen and forced a fumble. A.J. Hilliard recovered at the Arkansas 41 before a roughing the passer penalty on the next play immediately got the Aggies (4-0) into field goal range.
Taylor Bertolet's 38-yard field goal attempt on the final play of regulation was just wide right, but Allen hit Kirk in the end zone on the second play of overtime.
"I don't want to say it, but this is territory that we've been before," Brandon Allen said. "We've lost games in Round 4."
Kirk finished with eight catches for 173 yards. Josh Reynolds had three catches for 106 yards, including a 63-yard play to set up Tra Carson's 2-yard touchdown run with 2:50 left before catching the tying 2-point conversion.
Texas A&M overcame a two-touchdown deficit in the fourth quarter against the Razorbacks last year before winning in overtime in the game played annually in the Dallas Cowboys' NFL stadium built by Jerry Jones, a member of Arkansas' undefeated team in 1964.
The Aggies have won all four meetings since joining their former Southwest Conference rival in the SEC in 2012.
Kirk, the first freshman to have a 100-yard receiving game in his debut, now has three 100-yard games.
"We've got confidence in Christian," Aggies coach Kevin Sumlin said. "He's a big-play guy. He got a little tired tonight. We handed it to him, we threw it to him, he returned it."
The Aggies have won consecutive conference openers for the first time since 2004-05, when they were still in the Big 12.
Garrett has 6½ sacks, and the Aggies had two against an Arkansas line that hadn't allowed one all season.
But Bertolet, who earlier made kicks of 22 and 23 yards, pushed the kick to the right of the upright.
Brandon Allen completed 20 of 25 passes for 225 yards with a touchdown and an interception for the Razorbacks, who were coming off consecutive home losses to Toledo and Texas Tech.
This was a gut punch for the Razorbacks even if it didn't qualify as another kick in the rear as had been predicted by Kliff Kingsbury after the Red Raiders won in Fayetteville last week. Kingsbury's former boss is Sumlin.
"Ten years I've gone through this, and every win or every loss seems like it's so extremely high and so extremely low," Razorbacks coach Bret Bielema said. "It actually is easier for players and coaches, we go right back into prep and you don't have any time to feel sorry for yourself."