Twice on a crucible series of downs, the Kansas City Chiefs challenged E.J. Gaines.
The Chiefs' stick of dynamite, Tyreek Hill, who three weeks ago weaved his way through the Dallas Cowboys' seven-man-deep-drop prevent defense for a 56-yard touchdown, had the ball on Gaines' watch.
On first down, a large blocker tried to smother Gaines. On third down, the Chiefs drew up a pass that put Hill one-on-one with the Buffalo Bills' right cornerback.
While much of Sunday's attention was paid to Tyrod Taylor's return, offensive coordinator Rick Dennison's dicey strategies or rookie cornerback Tre'Davious White's game-sealing interception, Gaines' sparkling fourth quarter was highly material to Buffalo's 16-10 victory in Arrowhead Stadium.
"This means everything," Gaines said. "This was the most important win of our season right now.
"We needed this one just to keep the team together and keep on pushing forward and keep motivated. This team is ready for more wins."
Gaines grew up 9 miles away in Independence, Mo. About 30 family members and friends — even his high school's security guard — watched him clamp Hill over the final minutes.
They also saw Gaines, one of the Bills' cleanest players, get flagged for a preposterous unnecessary roughness penalty that could have cost them the game.
Hill had two offensive touches through the first three quarters. He caught a pass for 3 yards in the first quarter and ran for 16 yards in the third.
With the game on the line, Chiefs coach Andy Reid fed Hill, an All-Pro punt returner last year as a rookie who went into Sunday averaging 14.6 yards a catch this season.
"Explosive, a game-changer," Gaines described Hill. "His game is speed. You have to be aware of that. That's one thing we focused on was not letting him impact the game."
Hill was made busy enough to finish with 11 targets, three more than his previous season-high. And they sent him toward Gaines often.
Five minutes were left when the Chiefs called a first-down screen pass to Gaines' side.
Tight end Travis Kelce, all 6-foot-5 and 260 pounds of him, separated Gaines and Hill, an eclipse between two 5-foot-10 former track guys.
"That was something they had been doing to us with the screen game all day," Gaines said. "So (defensive coordinator Leslie) Frazier just told me, 'Next time, just trigger. Go and make a play for this defense.' That's what I did."
Among the 68 tight ends who have played at least 25 percent of their teams' snaps, Pro Football Focus graded Kelce the NFL's 15th-best run blocker.
But Gaines grappled them both. Despite being engaged in Kelce's block, Gaines got his right arm around Hill and slung them out of bounds.
"That was just an instinct play," Gaines said. "It was a clutch situation, and Coach Frazier definitely put us in places to make plays all day today."
Two plays later, on third-and-6, Alex Smith tossed into the left flat, where Gaines was alone. Hill had to reach for the pass, and in the nanosecond it took him to plant his feet, Gaines wiped him out on the spot.
"It's not something that you really think about," Gaines said of being one-on-one with Hill. "You practice breaking down and making good open-field tackles every day.
"That was just another tackle I happened to make, and I need to do that for my football team and my defense going forward."
Over a 12-play stretch in the final seven minutes, Gaines made seven tackles, three short of his career-high for an entire game.
Four tackles came over a five-play span on the Chiefs' penultimate drive, three more on their final, controversial possession.
All of it could have been ruined. After Buffalo's measly three-play, 14-second series, Kansas City reached the visitors' 36-yard line because of that phantom unnecessary roughness call on Gaines.
A slightly off-target first-down flare pass to Charcandrick West caused the running back to stumble down as he caught it. Gaines dove in for the tackle but rolled harmlessly over him, grazing a forearm across West's shoulder or back.
But down judge Phil McKinnely, a former NFL tackle and along with former Bills safety Steve Freeman the only retired players on an officiating crew, thought Gaines hit a defenseless receiver.
"It's frustrating because you try to make plays for your defense and not have penalties," said Gaines, flagged for one accepted penalty for 5 yards over his previous 20 games.
"That was just a crazy play and something I can't help the refs with. That's something they got to get together."
Three plays later, White intercepted the last pass intended for Hill.
The Bills went into victory formation with 71 seconds left.
"Now I won't be thinking about that penalty," Gaines said. "I'm going to sleep good tonight."