Lindsey Vonn and Maria Riesch begin a four-day duel for the overall World Cup title today.

After 31 races, four more at the World Cup finals will decide if Vonn gets her fourth straight title or current leader Riesch gets an elusive first.

The 26-year-old best friends have elevated their race rivalry to new heights this season in their closest battle for the giant crystal globe trophy.

The finals start with their specialist downhill discipline and ends Saturday with a giant slalom, their weakest event.

"This is crunch time. I'm sure it's going to come down to the last race," Vonn predicted yesterday.

Riesch has been runner-up for the past two years, but the German has never led so late in the season.

"That would be great tension until the end, to decide it in the GS on Saturday — but we will see," said Riesch, whose 23-point advantage can quickly vanish as race wins are worth 100.

"It would be a great dream coming true (to win) but, if not, then maybe next year or the year after," the double Olympic champion said. "I don't have to do this now."

Alpine racing has not seen such a showdown since Sweden's Anja Paerson edged her great Croatian rival Janica Kostelic by three points in 2005. On the same Lenzerheide slope, Kostelic would have won had she been 0.09 seconds faster in the GS finale.

Vonn smiled while thinking of the number-crunching permutations ahead.

"I've run a couple of scenarios through my mind how it could play out differently," she acknowledged. "I can't control what Maria's doing but I can control my skiing, so I'm going to give it my best shot."

The American defending champion arrives with fresh momentum after gaining ground at the weekend.

A career-best third place in GS at the Czech resort Splinderuv Mlyn was followed by a solid slalom result as Riesch surprisingly skied out.

"As you saw last weekend, anything can happen. I have to keep the same approach, and ski with intensity, focus and determination," said Vonn, who has already won the downhill, super-G and super-combined discipline titles.

Riesch reflected it was "not easy to keep cool" amid talk of her shrinking lead.

"It can go so fast from 96 (points) to 23. I try to just concentrate on my skiing and not calculate the points too much," she said.

The men's racing drama is set to peak in the downhill that opens the finals program today.

For the seventh straight year, the downhill globe is nearly certain to be lifted by Michael Walchhofer or Didier Cuche. Both seek a fourth discipline title, second only to the five won by Austrian great Franz Klammer between 1975-83.

Walchhofer, who leads by 14 points, is keeping his promise to retire at season's end with no regrets.

"This was always an important thing for me," the 35-year-old Austrian said after being fastest in training on Tuesday. "To be there until the end and really have the chance to achieve something."

The 36-year-old Cuche, who confirmed yesterday he will return next season, called the downhill finale "a perfect situation."

"It couldn't be better. It's great for the sport, and to be an actor in this drama is very enjoyable," the popular Swiss said.

Walchhofer's teammate Klaus Kroell can spoil the script, although he trails by 79 points.

Cuche is favored to win his first super-G title on tomorrow, with Walchhofer leading an Austrian trio holding outside chances.

Ivica Kostelic, the undoubted star of 2011, can also add crystal globes in super-G and the slalom on Saturday to his discipline title in super-combined.

The 31-year-old Croat clinched his runaway victory in the overall points race last weekend.

Both giant slalom titles have come down to the final race, despite Ted Ligety's three-win streak before Christmas.

Ligety holds a 77-point lead on Norway's Aksel Lund Svindal with Frenchman Cyprien Richard also in contention on Friday.

"It's a pretty good course for me," said Ligety, who seeks his third World Cup GS title.

The women's GS crystal will go to Olympic champion Viktoria Rebensburg of Germany or France's Tessa Worley after a spirited season-long battle.

However, their contest might just be a footnote to the Vonn vs. Riesch conclusion on Saturday afternoon.