The Gatorade Duel, is NASCAR Nextel Cup preliminary event to the Daytona 500 held annually in February at Daytona International Speedway. It consists of two 150-mile races, and serves as a qualifying race for the Daytona 500. The finishing order in the two 150-mile races, held on Thursday, determine the starting lineup for the Daytona 500 held on Sunday.

Qualifying for the Daytona 500 is unique in NASCAR. Only the two front row starters (the pole position and "outside pole") are determined by the ordinary qualifying process of timed laps. After the top two positions are locked in, the rest of the starting grid is set by the finishing order of these two races. Drivers participate in one of the two races. Half the field entered for the Daytona 500 races in the first race, and the other half the second. The finishing order of the first race fills the odd positions of the starting grid (inside of each row), and the finishing order for the second race fills the even positions of the starting grid (outside of each row).

The event began as twin 100-mile (40-lap) races. From 1959-1971, the races were counted with points towards the Grand National championship. Purses awarded were counted separately from those awarded in the Daytona 500. For 1968, the races were scheduled for 125 miles each, but were cancelled due to rain, and the starting lineup for the 1968 Daytona 500 fell back on the timed laps. In 1969, the races were extended to 125 miles (50 laps), which would require a fuel stop, and change the pit stop strategy.

For 1972, NASCAR's modern era commenced, and the races were dropped from the Grand National schedule as points-paying championship events. As part of Winston's changes to the series, races were required to be at least 250 miles to be included as official points events. The races continued, however, held as a non-points event. CBS began covering the race by the early 1980s, airing them tape-delayed and edited the day before the Daytona 500.

With the introduction of restrictor plates in 1988, the resulting reduction in speed and fuel consumption again allowed drivers to possibly complete the race without a pit stop. Nine times from 1988-2004, one of the races went without a caution, and without a pit stop by the winner. Starting in 2001, the races were shown live on television, as the Daytona 500 would rotate between FOX/FX and NBC/TNT from 2001-2006.

In 2005, the races were lengthened to 150 miles (60-laps), given a new name, the Gatorade Duel, and a revised format. In deference to NASCAR's new Top 35 exemption, the grids changed from even-odd qualifiers to a combination of top 35 even-odd from the previous year's owner points and then the rest of the drivers' by speed. A rain delay in 2006 saw the second race finish under the lights.

Starting in 2007, the Gatorade Duel will be shown live on SPEED, under the new broadcast agreement.