Bobby Hauck described the loss as "stinging" and said the locker room was quiet, and he acknowledged being concerned about how his football team would recover emotionally.
He has experienced difficult losses in his 2½ seasons as UNLV's coach but none quite like this one.
The Rebels were in control, leading twice by 21 points in the first half and by 17 at halftime, but UNR - assisted greatly by a highly questionable pass interference call - was at least as dominant in the second 30 minutes.
UNR scored three touchdowns in the fourth quarter to rally for a 42-37 victory Saturday at Sam Boyd Stadium to keep the Fremont Cannon blue for the eighth year in a row.
"It's a terrible feeling being so close and getting to that point where we should put our foot down their throat," Rebels cornerback Sidney Hodge said. "We just couldn't pull it out."
Now the Rebels (1-6, 1-1 Mountain West Conference) must find a way to put this defeat behind them with a trip to Boise State this weekend.
"They put a lot into this week," Hauck said. "They were emotionally involved in this game. So, yeah, I'm worried about the next week getting our guys back up to play. This is hard."
UNLV came out ready to make a statement against UNR (6-1, 3-0) and did so even before the game began by wearing all-gray uniforms with the logo of a red cannon on their helmets.
"Let me tell you something," Wolf Pack coach Chris Ault countered afterward, "that cannon ain't red. It's blue and silver."
But Ault was mystified by how his team came out, saying it "didn't play with any emotion" as the Rebels took leads of 21-0 and 28-7 and went into halftime up 31-14.
They overwhelmed the Wolf Pack, with Tim Cornett rushing for 108 yards and Nick Sherry passing for 150 in the first half. UNLV gained 325 yards and held the ball for 19:27.
Hauck said he warned his players at intermission to not look at the scoreboard, but the Rebels played the second half as if they couldn't wait for the clock to wind down.
"We were playing conservative," Sherry said. "We weren't taking chances. As an offensive mentality, you've got to be aggressive the whole time, and we kind of laid back and did what Coach said not to do. We looked at the clock."
Sherry said he was referring to being conservative as more of a mindset, but it also was a strategy. He tested the Wolf Pack deep in the first half, but UNLV tried to use its running game and short passing attack in the third and fourth quarters.
Hauck said he didn't want to be reckless throwing the ball with such a big lead, and the bigger issue was not being on the field enough to establish an offensive rhythm.
UNLV had the ball for 8:53 in the second half and was outgained 283 yards to 111. Cornett rushed for 21 second-half yards on six carries, and Sherry threw for 93 yards, with 47 yards on a touchdown pass to wideout Marcus Sullivan in the final minute.
"We needed to generate first downs, and we needed to stop them," Hauck said. "We did neither."
The Rebels also were done in by what appeared to be a horrendous call late in the third quarter that greatly impacted the game.
Hodge made an interception down the left sideline, even with UNR wide receiver Aaron Bradley going over Hodge's back and ripping off his helmet. When Hodge saw the flag, he thought offensive pass interference had been called, but the penalty was on Hodge.
Hauck called the penalty "game-changing."
Hodge, though, didn't put much blame on the call.
"One play's not going to make or break this game," Hodge said. "We had to execute all game. It's a 60-minute game. Yeah, it was a factor, but there was a whole bunch of stuff leading into the outcome of this game. But it would've been great to get that call, the way it's supposed to be."
Had the call gone the Rebels' way, they would have had the ball with a two-possession lead entering the fourth quarter.
UNR took advantage of the second chance when Stefphon Jefferson - who rushed for 185 yards and three touchdowns - scored from 3 yards 2:02 into the quarter to cut UNLV's lead to 31-28.
Sherry forced a pass on the following UNLV possession that was intercepted. The Wolf Pack then took the lead for good, 35-31, with 9:43 left on Devin Combs' 7-yard touchdown pass to tight end Zach Sudfeld.
Combs, who rushed for 111 yards and passed for 167, became the third backup quarterback to beat the Rebels this season. He filled in for Cody Fajardo, who didn't play because of a back injury.
Cornett said he received a text message after the game from a friend telling him not to quit "because you never know how close you are," but heeding such advice isn't easy after this kind of loss.
"That's the mindset you've got to have," Cornett said. "You've got to keep working and working because there are games out there that can be won, and I feel like the team needs to feel the same way. I feel like they will."
Contact reporter Mark Anderson at firstname.lastname@example.org or 702-387-2914. Follow him on Twitter: @markanderson65.