This past weekend's 24 Hours of Le Mans endurance sports car race concluded the same way it has 13 of the past 15 years: with an Audi victory.

The German automaker continued its reign over the world's most prestigious sports car race by fending off big-money challengers Porsche and Toyota. 
Audi R18 e-tron Quattro 24 hours of le mans 2014

REUTERS/ Regis Duvignau

The 24 Hours race is held every June in the French city of Le Mans, two hours southwest of Paris. The race is held on the 8.5 mile-long Circuit De La Sarthe, a mixture of purpose-built race track and public roads.

Circuit de la Sarthe and the 24 Hour race have reached near mythical stature in the automotive world. In fact, Bentley named its last two flagship sedans, the Arnage and the Mulsanne, after portions of the race track.

The 24 Hours of Le Mans is also the third race of the 2014 FIA World Endurance Championship season. 
2014 24 hours of le mans driver parade

REUTERS/Stephane Mahe

Even though Audi's week ended in triumph, the majority of it was far from smooth. Driver Loic Duval demolished the #1 Audi R18 e-tron quattro during a practice session, sending Duval to the hospital and engineers scrambling to build an all new race car just days before the race.

The #1 car was eventually reconstructed, but Duval was kept out of the race for medical reasons. 
Audi R18 Loic Duval Crash

AP

As the 55 cars lined up to start the race on Saturday afternoon, the truly unique nature of endurance racing became evident.

Unlike other forms of racing, endurance racing allows different classes of cars, ranging from purpose-built Le Mans prototypes like the Audi to production based- Porsche 911s, to race on the same track at the same time.  
2014 24 Hours of Le Mans

REUTERS/Regis Duvignau

As the cars jetted past the green flag, the blue-liveried #7 Toyota with former Formula One star Alexander Wurz behind the wheel and the #14 Porsche with its unique four-element headlights led the way. 
24 Hours of Le Mans 2014

REUTERS/Regis Duvignau

The Toyota TS040 Hybrid and the Porsche 919 Hybrid were entered by their respective manufacturers with the explicit mission of ending Audi's reign. As the race started, it seemed likely that this would happen.

The would-be challengers swapped leads for much of the first half of the race with the Audis waiting patiently for its new foes to slip up. 
2014 24 Hours of Le mans

AP

As actor Jason Statham famously said in the Le Mans documentary "Truth in 24, "It always rains at Le Mans." This year was no different ,as the skies opened up right just a few minutes after the start. 
Toyota Le Mans 2014

REUTERS/Regis Duvignau

As usual, crashes resulting from a slippery racetrack claimed quite a few cars like this Nissan-powered prototype from Greaves Motorsports, which collided with another car near the pit-lane. 
24 hours of le mans 2014

REUTERS/Regis Duvignau

To mitigate the dangers of exhaustion, each car is shared by a team of three drivers, with each driver prohibited from spending more than four hours at a time in the car. 
24 Hours of Le Mans Driver Change Audi

AP

As the race progressed, Audi suffered multiple turbo failures that required engineers to install new units during the race, while Porsche was plagued by electrical and suspension problems.

Toyota's lead car, the #7, was taken out of the race by a fatal electrical failure.
Porsche 919 2014 24 hours of le mans

REUTERS/Stephane Mahe

As the race plowed on, thousands of fan from around the world enjoyed the festive atmosphere at the circuit. Amenities included a Ferris wheel with a brilliant view of the track.
24 Hours of Le mans

REUTERS/Regis Duvignau

As the 24 Hours of Le Mans came to a close, the #2 Audi, manned by drivers Andre Lotterer, Marcel Fassler, and Benoit Treluyer, stood victorious next to the Michelin Man for the third time in four years. The trio held on under relentless pressure from Toyota and its corporate cousin, Porsche, by completing 379 laps covering more than 3,200 miles in 24 hours. 
Audi Win 24 Hours of Le Mans 2014

AP

In case any "Grey's Anatomy" fans are reading, Patrick Dempsey and his Dempsey Racing Porsche 911RSR finished 24th overall and fifth in the GTE-AM class. This was Dempsey's third appearance at the race and his best finish so far. 
Patrick Dempsey 2014 24 Hours of Le Mans

REUTERS/Stephane Mahe