After his Stage 18 win, Andy Schleck of Luxembourg has his sights set on a first Tour de France title. (Laurent Cipriani/AP)

Thomas Voeckler’s spirited run in the yellow jersey may finally come to an end, just three days before riders roll into Paris to conclude the 2011 Tour de France.

After finishing behind defending champion Alberto Contador twice, 26-year-old Andy Schleck blew past his rival to win Stage 18 in the Alps on Thursday, whittling Voeckler’s lead to a mere 15 seconds.

Schleck will look to snatch the lead away for good during Friday’s 19th stage, which traverses the famed Alpe d’Huez and features three challenging climbs over a short, but physically trying 68-mile race. The 168 riders must brave 21 steep switchbacks to a peak elevation of 6,069 feet.

“I told the team yesterday that I had this in mind. I wasn’t going to be fourth in Paris. I said I’d risk it all. ... It’s my character: I’m not afraid to lose.”

It’s been quite a run for Voeckler, who has held the yellow jersey for 10 days and is trying to become the first Frenchman to win the Tour since Brenard Hinault in 1985. And while the fan-favorite has maintained he has a “zero percent chance” of winning, his efforts have enthralled the host country.

For Contador, Thursday’s climb may have taken him out of the running for a fourth title. His balky right knee was a noticeable impediment and he was receiving anti-inflammatory treatment when Schleck bolted to the front of the back.

Schleck’s older brother Frank currently sits in third place, 1 minute, 8 seconds off the pace, while Australian Cadel Evans has fallen to fourth (1:12). Another solid ride from Andy Schleck could bring the Luxembourg native his first Tour victory.

Just how challenging is the climb up Alpe d’Huez? Washington Post sports writer Andrew Beyer decided to find that out for himself back in 2005. At 61, Beyer was hardly in Tour de France shape, but he was plenty fit as his spot on his D.C. bike club’s “Order of the Cast-Iron Crotch” high-mileage honor roll would suggest.

Here’s how Beyer described the ride in his July 3, 2005 column:

“By mid-ride I realized why Alpe d'Huez has such a formidable reputation: It is relentless. Most climbs give riders an occasional flat or downhill respite. As the road to Alpe d'Huez keeps going up and up, the switchbacks can be demoralizing. Looking up, I felt as if I were at the bottom of a staircase; I could see the riders on the tiers above me, and it seemed like an endless task to get where they were.”

In other news, Laurens “tough as nails” ten Dam doesn’t look too worse for the wear after his horrific crash earlier this week.