From left to right, Ryder, Darlene Nestor, Chance and Gryffin are shown in a family photo. Courtesy Jennifer Sanders

A 10-year-old Colorado boy who likes to play Mario Kart and drive go-Karts grabbed the wheel of his great-grandmother's speeding car when she passed out and guided it safely off the highway.

While Gryffin Sanders was handling the Buick sedan at 60 mph, his little brother, Ryder, 4, was in the backseat oblivious to the drama and playing on his iPad.

The boys were riding with their great-grandmother Darlene Nestor - who the boys call Grandma Great - down a Colorado highway July 26 from Cheyenne Wells to Golden.

"My grandma great was talking about some of the wildlife and stuff about the Great Plains when she passed out in the middle of a sentence," Gryffin told ABCNews.com.

In that moment, Gryffin admits he was a little scared. He tried a couple times to shake her awake, but couldn't rouse her as the car barrelled down the highway.

The boy then decided he had to grab the wheel.

"I could see over the dashboard while I was driving, so I had an idea of where I was driving into. I couldn't get to the brakes because my grandma great was in the way," said Gryffin.

"There was one car that was pretty far away," Gryffin recalls as he drove his family away from oncoming traffic and into safety.

"I just drove the car to the right," Gryffin said, and guided it into a muddy ditch. His great-grandmother's foot eventually fell off the gas pedal and that, combined with the mud, brought the vehicle to a stop.

Still entranced by the video game on his iPad, Ryder had not even realized all the commotion that was taking place towards the front of the car. When the car came to a stop, Gryffin turned around to tell to Ryder to continue playing on his iPad and that he was "doing great!"

He credits the hours he's spent playing the video game Mario Kart and his hobbies of driving go-karts and ATVs for being able to handle the car.

Nestor bragged about the boy.

"I'm so proud of him that he saved so many lives that day even in oncoming traffic," she said. "He's always been a great kid."

She added, "All my great grandkids and grand kids are great."

Gryffin is trying to take it in stride.

"I want to be humble about this," he said.

He even asked that the couple who stopped and called 911 get some credit.

Mike Glidden and his wife were the first people to stop and help on the scene.

"His wife called 9-1-1 and two others helped get grandma great breathing again," said Gryffin.

Nestor was taken to the hospital shortly after the incident. She said she is doing fine and is recovering from the minor heart attack