(CNN) -- Rafael Nadal failed to clinch the year-end No. 1 ranking for the third time in his career after suffering a shock defeat at the Paris Masters on Saturday.
The form player of the men's tennis season after coming back from long-term knee problems, Nadal could have added to his 2008 and 2010 feats by beating David Ferrer and reaching the final of the penultimate tournament on the calendar.
However, he lost 6-3 7-5 to his third-ranked compatriot, who will defend his title in Sunday's final against Novak Djokovic.
The Serbian earlier kept alive his hopes of being year-end No. 1 for the third successive year by beating 17-time grand slam champion Roger Federer in Saturday's opening semifinal.
"I played maybe my best match this season," Ferrer said after ending a nine-match losing run to Nadal.
"Paris is very special for me. I made my first final of a grand slam in Roland Garros; last year I won my first Masters 1000 title; now I'm in the final again in Paris."
Second-ranked Djokovic had to come from behind to win 4-6 6-3 6-2 against the veteran Swiss, who is showing signs of improved form.
Both matches were dress rehearsals for the ATP World Tour Finals in London next week, where Nadal and Ferrer will be in Group A along with Tomas Berdych and debutant Stanislas Wawrinka.
Defending champion Djokovic and six-time winner Federer will be in Group B with Juan Martin del Potro and Richard Gasquet.
"I was pretty happy with my level of play," said Federer, who will equal Ivan Lendl's record 12 consecutive appearances at the season-ending event.
"I wish I could have kept it up for a bit longer and put him under pressure, but Novak battled well to stay in the match in the second set and the third set.
"I had my chances in the second and third sets. Disappointed right now, but overall it was a good week for me."
On Friday, Federer avenged his Swiss Indoors final defeat by Del Potro -- and the Argentine's week got even worse when he was robbed at Paris' Gare du Nord train station en route to Britain.
His confidence will be shaken after losing his most prized possession -- a rosary that was blessed by the Pope in Rome this year, which was in a briefcase stolen as he checked in.
"My Rosary blessed by Pope Francis, I carried it everywhere," the 25-year-old told the ATP Tour website.
"That's what matters most to me. I was finishing the check-in and was asked for an autograph. I turned around to sign it and, within 20 seconds, it was stolen."
Meanwhile, the Italian women's team took a big step towards a fourth Fed Cup title after winning both singles matches on the opening day of the final against an under-strength Russia Saturday.
Italy, whose last title came in 2010, saw its top-ranked player Sara Errani thrash Irina Khromacheva 6-1 6-4 after Roberta Vinci battled to a 5-7 7-5 8-6 win against Alexandra Panova.
Both Russians were making their debut in the largest team tournament in women's international sport, which featured 97 nations this year, as the country's top 11 players were unavailable.
The final clashes with the WTA Tour's Tournament of Champions in Bulgaria, a second-tier end-of-season event where Russia's Anastasia Pavlyuchenckova lost to Sam Stosur in Saturday's semis and Romania's Simona Halep beat Serbian Ana Ivanovic.
The International Tennis Federation, which plans to move the Fed Cup final back a week next season, announced Saturday that Tunisia will be banned from the men's 2014 Davis Cup tournament after refusing to allow one of its players to compete against an Israeli.
Malek Jaziri had been due to play Amir Weintraub at last month's Tashkent Challenger.
"There is no room for prejudice of any kind in sport or in society," ITF president Francesco Ricci Bitti said. "The ITF board decided to send a strong message to the Tunisian Tennis Federation that this kind of action will not be tolerated by any of our members.
"The board felt that suspension from Davis Cup, a competition that was founded 113 years ago to encourage better understanding through sport, would provide a good lesson for the federation and a fitting penalty for their unfortunate action."