DALLAS — It’s been a long, difficult season for the Tulane Green Wave, but there’s a good case to be made that it hit bottom Saturday night at cold, blustery and nearly empty Gerald J. Ford Stadium.

It’s hard to imagine a more complete loss than the 49-21 bashing the Green Wave suffered at the hands of SMU.

Not only was Tulane (3-8, 1-6 American Athletic) dismantled in every phase of the game by a team that came in 1-9 and ranked near the bottom of the Football Bowl Subdivision in practically every defensive category, but it also lost starting quarterback Tanner Lee, who had been playing through a broken finger on his throwing hand, to an apparent re-injury of that hand in the third quarter.

“Frustrating,” Tulane coach Curtis Johnson said, shaking his head. “Very frustrating.”

SMU quarterback Matt Davis left the Tulane defense thoroughly baffled and helpless with his fakes and his running ability, rushing for 156 yards — including a 65-yard breakaway — and throwing for 165 as the Mustangs (2-9, 1-6) moved the ball at will. SMU posted its three longest drives, all longer than 90 yards, and its highest point total of the season.

Offensively, the Green Wave had its moments, notably 111 combined rushing/receiving yards from Dontrell Hilliard and touchdown passes of 27 yards from Lee to Larry Dace III and 2 yards by backup quarterback Jordy Joseph to Charles Jones II. But there were far too few of those to go around.

Lee left the game midway through the third quarter after taking a big hit from defensive tackle Deon Green on an incomplete pass. Trainers examined his right hand on the field before he was taken to the locker room for evaluation. He completed 9 of 22 passes for 103 yards.

Joseph was 4-for-11 for 25 yards.

“It’s crazy to lose to a 1-9 team,” defensive tackle Tanzel Smart said. “They came out with a chip on their shoulder because they didn’t have anything to lose. It was very shocking the way we lost this game.”

The Green Wave defense got off to a strong start, holding SMU to back-to-back three-and-outs. But the Mustangs got on the scoreboard first anyway when defensive end Zach Wood slipped past Tulane long snapper John Leglue to block Andrew DiRocco’s 40-yard field goal attempt — DiRocco’s first miss of the season.

The ball caromed into the hands of SMU’s RC Cox, who raced untouched 72 yards to the end zone for a 7-0 lead.

“That blocked kick gave them a lot of steam,” Smart said. “Coaches always talk about facing adversity. We probably didn’t take that too well.”

From that moment, the Wave had no answer for the SMU offense, which followed that score with two 90-plus-yard drives and converted eight consecutive third downs in cruising to a 35-7 halftime lead.

“Our defense played good for about a series and a half, then after the blocked kick, it was just downhill,” Johnson said, “We didn’t tackle well today, and we never got our running game going.”

By that time, the Tulane had allowed 335 yards, including 135 combined rushing-receiving yards and three touchdowns from running back Xavier Jones, who finished with 105 rushing and 44 receiving, and 68 yards and a score on the ground by Davis.

Davis also completed 14 of 20 first-half passes, and receiver Courtland Sutton added a 30-yard bomb on a trick play that Darius Joseph grabbed just in bounds to set up a touchdown.

“They ran a lot of quick handoffs and quick plays,” Smart said. “They’ve got a lot of fast guys, and the quarterback got a lot of yards on the quick stuff.”

While the Tulane defense vanished without a trace, the offense was barely visible, despite facing an SMU defense that entered the game ranked last in the nation in points allowed. All the Green Wave could muster in the first half was Lee’s touchdown pass to Dace to cap a 71-yard drive. Other than that, Tulane managed a mere 33 yards in the half.

The second half looked better as the offense finally showed some life with 224 yards and touchdown drives of 85 and 63 yards. But with one game left, moving on from such a demoralizing performance won’t be easy.

“You’ve got to just keep fighting,” Johnson said. “That’s what you do. You keep fighting. ... And to our credit, we came out and scored a couple touchdowns and moved the ball in the second half.”

“We weren’t ready to play, and they took advantage of that,” Hilliard said. “We were lax as a team. They were ready, and we were looking at what the records showed instead of playing our game.”