HENDERSON, Nev. -- The Las Vegas Raiders were a mere 103 seconds away from sweeping the Kansas City Chiefs, improving to 7-3 and showing the world on a prime-time stage that, yes, they were indeed for real. A force with which to be reckoned.

Then, quarterback Patrick Mahomes happened.

In 75 seconds, Mahomes matriculated the defending Super Bowl champs 75 yards down the field, finding a ridiculously wide-open Travis Kelce in the end zone for a 22-yard touchdown -- not merely breaking the Raiders' Silver and Black heart, but pulling it from their chest, taking a bite out of it and tossing it in the Allegiant Stadium grass.

Chiefs 35, Raiders 31.

And truly, the Raiders never recovered. Because if you're looking for a point in time when Las Vegas' season went off the rails after such a promising start, it was here, with Raiders safety Johnathan Abram in a different zip code on a blown coverage that would serve as an omen for the secondary down the stretch.

Sure, finishing 8-8 is an improvement from last season's 7-9 record and better than the 4-12 mark the Raiders had in coach Jon Gruden's first season back with the franchise in 2018.

It's just that consecutive late-season fades raise so many questions after the Raiders were 6-4 in 2019 and lost five of their last six and then this season went from 6-3 to 7-8 entering the wild finale at Denver -- in which, for the third straight game, the defense allowed the opposition to get into range to win after the Raiders' offense had taken a late lead.

Against the Broncos, though, Maxx Crosby blocked Brandon McManus' 63-yard field goal attempt and the Raiders survived 32-31.

"We definitely don't make it easy on ourselves," said Crosby, who had seven of the Raiders' 21 sacks this season.

"The defense as a whole, we've got to be locked in, start to finish. I feel like there's good moments, then there's lack of focus, lack of detail, lack of intensity at times. Especially this year being on the road and playing at home in front of nobody in an empty-ass stadium, it's a lot different."

A year ago, the Raiders were legitimately three plays away from being a 10-6 team and in the playoffs. They were also three plays away from being 4-12, so 7-9 seemed fair.

This season, the Raiders woulda, coulda, shoulda beat the Chiefs, Los Angeles Chargers and Miami Dolphins at home to go 11-5 and join the postseason party. Then again, they probably should have lost at the Chargers, at the New York Jets and in Denver.

So it all comes out in the wash for a team that went 6-2 on the road but just 2-6 at home, right? Even in the third year of a rebuild that went down in a pandemic in the first year of a move from Oakland to Las Vegas?

"Yeah, we're going to give our coaches some time off, and our goal is not 8-8," Gruden said Monday in his final virtual media conference of the season. "Our goal is to win a championship, and you shouldn't go on a cruise or go on a vacation when you're 8-8. We've got to take a good look at how we can close the gap. We feel like we did to a degree with the best teams in the league, but we're not there yet."

Indeed, the Raiders beat the Chiefs at Arrowhead Stadium for the first time since 2012. They beat the New Orleans Saints in the first regular-season NFL game in Las Vegas history. They thumped the Cleveland Browns on the road. Playoff teams all.

They went 4-2 in the AFC West, same as the Chiefs.

Still, the Raiders need a closer.

And a revamped defense. Because even after firing Paul Guenther as defensive coordinator on Dec. 13 and replacing him on an interim basis with defensive line coach Rod Marinelli, the Raiders' defense had trouble creating pressure and turnovers.

Names already mentioned as potential candidates include Raheem Morris, Gus Bradley and Joe Barry, as Gruden wants to maintain a 4-3 front.

The Raiders also got next to nothing out of their rookie class, not to mention their past two free-agent hauls.

"Obviously, the injuries to Trent Brown, those are major, major problems, not getting him on the field," Gruden said of the handsomely paid right tackle, who has appeared in 16 games over the past two years, five this season, after signing a four-year, $66 million contract in 2019 and is a prime cut candidate this offseason.

"Tyrell Williams didn't play one game. Marcus [Mariota] got hurt, missed a couple months, really couldn't ever really compete. [Lamarcus] Joyner had the virus. [Cory] Littleton had the virus. [Nick] Kwiatkoski got hurt and had the virus. We saw Maliek Collins get hurt. It was disappointing, but at the same time, I compliment those guys for hanging in there and continuing to fight all the way to the end."

Offensively, there were statistical bright spots, with tight end Darren Waller setting a franchise record with 107 catches for 1,196 yards and nine touchdowns, and running back Josh Jacobs becoming the third Raiders player to rush for at least 1,000 yards in consecutive seasons. Both garnered Pro Bowl selections.

There was also quarterback Derek Carr passing for a career-high 4,103 yards, despite missing most of one game with a groin injury.

And kicker Daniel Carlson set a franchise record with 144 points scored, which was tied for the NFL lead.

So where did it all go so wrong after that 6-3 start and Carr hitting Jason Witten for a 1-yard TD pass with 1 minute, 43 seconds to go against the Chiefs?

Carr echoed Gruden's training camp mantra of the best ability being availability, something the Raiders' young players especially struggled mightily with in 2020.

"You have to sacrifice going out and you have to sacrifice going to bed early," Carr said after the season finale. "You have to sacrifice some things to make sure you're available all the time. I think there are some guys on our team -- if they're still around -- that are going to learn how to sacrifice some things. If we want to go where we want to go, we have to be able to sustain it. We started great the last two seasons ... but we haven't finished strong.

"It's a work in progress. We feel like we're heading in the right direction, if I'm being honest. We feel like we're heading the right way. We just have a lot of work to do."

And in a perfect world for the Raiders, the work would end with Carr taking a bite out of the Chiefs' heart.