When Brad Keselowski wins a race, it's often because brain power trumps horsepower.

That was certainly the case Sunday at Dover International Speedway, where Keselowski seized the lead in the Chase for the NASCAR Sprint Cup with his victory in the AAA 400.

Once again, the tortoise beat the hare. No, Keselowski's No. 2 Dodge wasn't slow, but it wasn't among the fastest cars in the race. The Toyotas of Joe Gibbs Racing teammates Kyle Busch and Denny Hamlin and the Chevrolet of Jimmie Johnson spent more than 95 percent of the afternoon in the top three positions, leading a combined 384 of the 400 laps.

It was a decision made before the race started, however, that enabled Keselowski to win.

In tuning his Penske Racing engine for competition, crew chief Paul Wolfe opted for a configuration that struck a balance between horsepower and fuel economy. The Gibbs engines, on the other hand, were tuned for maximum horsepower.

When Matt Kenseth's collision with the Turn 2 wall brought out the fourth caution on Lap 308, Busch, Hamlin, Johnson and Keselowski came to pit road for tires and fuel, as did the four other drivers on the lead lap — Jeff Gordon, Clint Bowyer, Kasey Kahne and Carl Edwards.

The race restarted on Lap 316. One circuit later, Kenseth crashed again, necessitating caution No. 5. All lead-lap cars stayed on the track except those of Gordon, Kahne and Mark Martin, who had returned to the lead lap under the previous caution as the highest-scored lapped car. Â

The race restarted on Lap 322, and at that point the die was cast. If the race ran without caution the rest of the way, as it did, the Gibbs cars would be forced to pit for fuel late in the race, which they did. When no yellow flew by Lap 350, Johnson was forced to scale back his lap times and give up positions in order to stretch his fuel mileage to the end of the race.

Keselowski, who began saving fuel as soon as he left the pits on Lap 309, was nevertheless able to maintain sufficient speed to hold off Gordon and Martin.

The bottom line is that Keselowski and Wolfe had all their options covered, in part because of the pre-race choice of the tuning package, and in part because Wolfe was first to grasp the big picture and realize that the race had a green-flag feel that could well take it to the end without another caution.

For all other teams, the prudent choice would have been to come to pit road with Gordon, Martin and Kahne, but to do so would have meant giving up track position.

Then again, there were only nine cars on the lead lap at the time.

Hamlin made a definitive statement after the race.

"They're not going to beat us on the track — that's just plain and simple," Hamlin said, and given the speed of his cars in the first three Chase races, he's probably right.

Nevertheless, Keselowski has won twice in the Chase to Hamlin's once. Keselowski holds the series lead. Hamlin is third, 16 points back, with a car fast enough to have won all three races.

It was the gas tank that flummoxed Hamlin, who ran out of fuel at Chicagoland, for the second time in three weeks.

It was the think tank that propelled Keselowski to victory on Sunday — and just might earn him a championship.