Two years ago at O.Co Coliseum, Chiefs running back Jamaal Charles celebrated a touchdown and promptly was baptized in beer and pelted with who-knows-what-else by salty Oakland Raiders fans.

There is such a history of hostility in this rivalry that Chiefs legend Len Dawson laughed when he considered the peril he might have been in had he ever chosen to, say, wander towards the Raiders’ stands waving a ball.

“They’d have loved me to have come there,” he said, “so they could choke me.”

But it was safe passage here Sunday for Chiefs’ rookie cornerback Marcus Peters, the Oakland native who had just plucked a crucial interception and run it back 58 yards in the fourth quarter to set up the go-ahead touchdown in Kansas City’s 34-20 victory.

As Peters immediately took off his helmet and marched toward Section 142 holding up the ball, no one in a fan base that boasts “a black hole” in the stands hurled anything at him — maybe not so much as an epithet.

To the contrary:

They made way for his mother, Doreen, to lean over a railing in her red Chiefs No. 22 jersey and hug him and accept the ball from him and clasp it tight for the rest of the game.

And maybe she’s even cradling it still right now.

“I’m probably going to cry later,” she said, standing in front of her third-row seat as the clock ran down on the Chiefs’ sixth straight victory.

But not at that moment.

This was the time to bask in and appreciate where this all started for the still-volatile rookie whose turbulent but ultimately triumphant day in some ways was a microcosm of his journey to Kansas City.

For a while on Sunday, it was almost too much to bear for the young man with “OAKLAND” tattooed vertically down his back, framed by the words “FAMILY” and “FIRST.”

It’s hard to quantify exactly how many people in the crowd of 55,010 were here explicitly to see him play. But maybe the most telling point in his mind was how many he playfully estimated it to be.

“The town,” he said, smiling. “I brought the whole town.”

No doubt that was what it felt like to him.

“You grow up riding past the stadium, and then you end up coming to play in it,” his mother said. “How do you bottle that up, right? How do you bottle that up? It’s hard, so I understand.

“But he got it together, and he did his job.”

Even if all of his circuits were crackling and, in fact, sizzled over at times.

That’s why he was still feeling queasy after the game and it probably helps explain why he made some uncharacteristic mistakes early.

It also speaks to why he had lapses trying to strip balls instead of making tackles, and got out of position a few times, and committed a pass-interference penalty, and had an unsportsmanlike-conduct penalty that left him ranting and, in fact, throwing up on the sideline early in the fourth quarter.

“I was just too fired up,” he said.

It wasn’t the first time.

That’s sort of a mixed blessing for the Chiefs, who still are working to refine and harness Peters’ emotions but found him available at No. 18 in the draft largely because of a couple tantrums during his collegiate career at Washington.

So it was that after a game in which Peters had that interception, forced a fumble, made six solo tackles and broke up two other passes, coach Andy Reid would talk about his need to learn from this game and not get “emotionally tied up” again.

So it was that Reid also would smile and add, “You love that he loves to play the game.”

This day illuminated that in yet another way, from Peters’ pre-game dancing and straying from running into the locker room to hug his father, Michael, who also was wearing one of his son’s Chiefs-model jerseys … but made it a point to wear a black coat over it.

“For you to come into the Black Hole,” Peters joked later, referring to the nickname of the Raiders’ stadium, “you’ve got to throw on a little bit of black to survive, man.”

Speaking of survival, it’s hard to know how Peters wouldn’t have simply imploded if the trajectory of the game hadn’t changed late.

After the Raiders went ahead 20-14 and Peters’ was cited for unsportsmanlike penalty, the Chiefs went three and out … and Peters, perhaps still calming down, was scorched on back-to-back passes.

One to Amari Cooper was good for 23 yards to the Kansas City 33-yard-line.

Then Peters, and the Chiefs, caught a break when Derek Carr overthrew an open Michael Crabtree.

On the next play, Josh Mauga intercepted Carr to change the game and set up the tying touchdown.

Somewhere amid all of this, teammates from Eric Berry to Alex Smith helped refocus Peters by urging him to cool down.

His mother, too, apparently made an impact after locking eyes with him and blowing him a kiss.

Soon came his team-leading fifth interception.

“Priceless,” she said. “Priceless.”

All the more so that they were allowed to share the moment as they were, a hometown favorite trumping a harsh rivalry.

“It’s love, man,” Peters said. “I truly appreciate that they let my mom and my family come in here with all that red on.”