Chad Greenway's grandfather had never watched him play in an NFL game in person before Sunday. Tom Greenway is an 82-year-old lifelong dairy farmer awaiting two knee replacements.

"He's mad because he can't go work on his tractors," Chad said.

His grandson provided him a nice consolation prize.

One week after playing a career-low 16 snaps, Greenway gave himself and his family a memory that will last a lifetime — a 91-yard interception return for a touchdown in a 31-14 rout of the San Diego Chargers.

His return was the fifth-longest in Vikings history, and this one will be remembered by the chaos that ensued around it.

Two coaches — including head coach Mike Zimmer — got bowled over by an official along the sideline as seven of Greenway's teammates provided a personal escort to the end zone.

Any play of that nature is memorable, but the emotion in Greenway's cracking voice afterward revealed just how much the moment meant to him: "You can't write the script any better."

Greenway's role has been diminished in the twilight of his career. He's no longer an every-down linebacker. He spends more time on the sideline than the field now.

But he's handled the change in typical Chad Greenway fashion. He's a consummate pro.

"I've tried to do things right my whole career," he said.

He was rewarded with a special play on an emotional day.

Greenway purchased 24 tickets for family and friends — the largest allotment he's ever requested for an NFL game. That group included his grandfather, his dad's dad.

Greenway's father, Alan, died last December. Chad said he felt his father's presence Sunday, both with his grandfather there and when Philip Rivers' pass bounced off his receiver's hands into Greenway's arms.

"You've just go to think my dad tipped the ball up," he said.

His touchdown return was part inspirational, part wacky.

Greenway avoided one tackle and then had nothing but teammates running between him and the end zone. Well, that and 91 yards of turf, a long way for a 32-year-old linebacker.

"I don't run 91-yard sprints much," he said. "And I'm not going to start because of this play either."

Greenway's teammates surrounded him with a convoy as he ran down the sideline. Cornerback Captain Munnerlyn motioned to Greenway at one point.

"I was telling him to hurry up and get into the end zone," Munnerlyn said.

Cornerback Terence Newman, 37, said he doesn't normally run all the way to the end zone on turnovers, if he's not needed. But he joined the pack, too.

"I knew Chad would probably run out of gas at some point," he said.

Nope, Greenway reached the end zone without having to stop for oxygen.

"He's still got some moves in him," safety Harrison Smith said. "He's got some wheels."

OK, let's not go overboard.

"Believe or not," Greenway said, "I did play a lot of offense in high school, so I knew what to do with the football."

Zimmer and secondary coach Jerry Gray would have loved to seen Greenway's moves, but they were toppling over each other. An official running down the sideline collided with Gray, who then knocked over Zimmer like a human domino.

"I actually didn't see the touchdown," Zimmer said.

The players on the field didn't know their coach got flattened.

"Oh dang," Newman said. "I'll be looking for that tomorrow when we watch it."

The Vikings bench received an unsportsmanlike-conduct penalty for being too close to the field during the return. Greenway cringed when he saw the flag; "I was thinking, 'You can't be serious.' "

No worries. The penalty was assessed on the kickoff.

Greenway likely will be struck by something on the video. The convoy from his teammates, the joy they felt running with him.

It was an ultimate sign of respect for a veteran.

"Once we saw it was Chad with the ball," Smith said, "we were all like, 'We have to get him in the end zone.' Everybody loves him. He's our guy."

An hour after the game, Greenway returned to the field with his family members to take photos.

It was a perfect script, indeed.

Chip Scoggins chip.scoggins@startribune.com