Updated

Nate Romine has gone from buried on the depth chart to under center in a little more than a month.

The Air Force freshman quarterback filled in for injured starter Karson Roberts on Thursday night and nearly helped the Falcons snap a long losing streak. Romine ran for a touchdown and threw for another in a 27-20 loss to San Diego State.

"He did a good job," Air Force coach Troy Calhoun said. "He's got a ways to go."

Romine provided a spark that helped Air Force (1-6, 0-5 Mountain West) take a 20-6 lead heading into the fourth quarter.

It wouldn't last as the Falcons lost their sixth straight. They have been to six straight bowl games under Calhoun.

The Aztecs (3-3, 2-0) scored 21 straight points in the final quarter to escape with the win even with their struggles in the kicking game. San Diego State is 2-151-1 in program history when trailing by 14 or more points in the final quarter. The only other time the Aztecs rallied like this was at Air Force on Sept. 18, 1993, when they erased a 17-point deficit in a 38-31 win.

"We played our souls out," Calhoun said. "Hats off to San Diego State, winning a game down the stretch."

Quinn Kaehler finished 15 of 26 for 249 yards and three touchdowns, including two in the fourth quarter. Donnel Pumphrey had 117 yards rushing and scored the game-winning TD with 1:39 remaining.

Romine scored on a 16-yard run and threw a 71-yard TD pass for the Falcons in a game they didn't know would even be staged — because of the partial government shutdown — until it was given the official go-ahead about 27 hours before kickoff.

Will Conant made two long field goals, including a 52-yarder that bounced in off the left upright. His counterpart, Wes Feer, had a field goal and an extra point clang away no good off the same left goal post.

When Kaehler hit Pumphrey for a 20-yard TD early in the fourth quarter to begin San Diego State's comeback, coach Rocky Long sent out backup kicker Seamus McMorrow, who made the extra point.

A few plays later, Kaehler found a wide open Ezell Ruffin for a 62-yard score. But McMorrow had his point-after attempt blocked by Troy Timmerman, making it 20-19.

After forcing the Falcons to punt, Kaehler marched the Aztecs down the field and Pumphrey punctuated the winning drive with a run up the middle for a score. Kaehler threw a pass to Tim Vizzi for the 2-point conversion.

"Quite frankly, my biggest concern coming into the game was whether or not we could tackle Pumphrey," Calhoun said. "I've seen him all season long, he's just extremely electric. A couple of times we were in pretty good position and he gave us a wiggle and a juke and couldn't get him down."

The Aztecs have won three straight to even their record. According to San Diego State, of the 45 schools that opened 0-3 since 2010, the Aztecs join Houston (2012) as the only teams to even its record at 3-3 after six contests.

Just 40 days ago, Romine was the fourth-string QB for the Falcons. He moved up when Kale Pearson suffered a season-ending right knee injury in the opener and again after backup Jaleel Awini was declared ineligible by the academy.

Romine received the call to go in Thursday night shortly after starter Roberts came off the field in the first quarter with a concussion. Romine directed a scoring drive in his first series, capping it off with a 16-yard TD run early in the second quarter.

His 71-yard TD pass to Sam Gagliano was the longest by a Falcons QB in four years.

San Diego State controlled the clock and outgained the Falcons in the first half, only to trail 10-6 when Conant connected on a 48-yard field goal on the last play before halftime.

For a third straight week, the Falcons let a halftime lead slip away.

Hours before the game, Defense Secretary Chuck Hagel made the decision that football games and other sports will go on at the military service academies through the end of the month. The issue will be reassessed later this month if Congress has still not passed a budget to fund the federal government.

Air Force is off next weekend before hosting Notre Dame.

"We've got guys right now that are really, really disappointed," Calhoun said. "I think anytime you apply yourself and you're dedicated, it's going to happen that way."