A second half goal from Stewart Downing ensured Liverpool avoided an unwanted record Thursday as the English Premier League outfit edged Russia's Anzhi Makhachkala 1-0 at Anfield to bolster their Europa League hopes.

Downing's well taken 53rd-minute strike means Liverpool avoided two straight European home losses for the first time in their history after their recent hiccup against Italy's Udinese and they now lead Group A with six points from three matches.

Juan Martin del Potro secured his place in the ATP World Tour Finals on Thursday after Rafael Nadal's injury-enforced withdrawal from the eight-man season-ender opened up another vacancy.

The Argentine, who had already increased his qualification hopes for London by winning the Vienna title last weekend, was delighted to make it into the finals for the third time.

World number one Victoria Azarenka remains in suspense as to whether she will capture the year-end top spot after losing to Serena Williams for the fifth time in five meetings this year on Thursday.

The Belarusian's 6-4, 6-4 loss to the American in the WTA Championships means she may have to beat Li Na, the former French Open champion from China, on Friday to be sure of becoming number one at the end of 2012.

David Stern said Thursday that he will retire as commissioner of the NBA on February 1, 2014, exactly 30 years after taking the job and guiding the league and its superstar players to worldwide fame.

Stern, who announced his decision at an NBA Board of Governors meeting, will be replaced by current NBA deputy commissioner Adam Silver.

U.S. ski star Lindsey Vonn dismissed talk Thursday that her campaign to race against men was a mere public relations stunt, although she admitted she only had a slim chance of seeing her wish come true.

"It's a serious wish on my part. I already discussed this a few years ago with my coaches and friends," Vonn told journalists in the Austrian resort of Soelden, where she was preparing to race the giant slalom in the opening World Cup event Saturday.

Sporting director Sam Michael is adamant that McLaren will not throw in the towel in this season's Formula One title battle, saying the team is targeting wins in the final four races of the season.

Red Bull top the drivers' and constructors' championships after three successive victories for two-time defending champion Sebastian Vettel.

Victoria Azarenka had to draw on all her reserves by saving two match points in a heroic three-hour six-minute tussle with Angelique Kerber in the WTA Championships.

The top-seeded Belarussian beat the German revelation 6-7 (11/13), 7-6 (7/2) 6-4 in an encounter full of magnificent rallies and surprises. Her win leaves Azarenka needing just one more win to guarantee her finishing the year as world number one.

Micah Richards pointed the finger at coach Roberto Mancini after Manchester City fell to a 3-1 loss at Ajax that left their Champions League ambitions in tatters.

City were well beaten at the Amsterdam ArenA on Wednesday evening, but Richards felt that matters were not helped by Mancini's decision to switch to a three-man defense after the visitors fell 2-1 down in the second half.

Los Angeles Lakers superstar guard Kobe Bryant will miss the team's final two pre-season NBA games because of a sore right foot, the team announced on Wednesday.

Bryant hurt his foot in the third quarter of a loss Sunday to Sacramento and will be re-examined this weekend by doctors ahead of next Tuesday's NBA season opener, when the Lakers play host to the Dallas Mavericks.

Schalke piled on the misery for Arsenal as the German side struck twice in the closing stages to clinch a shock 2-0 win in Wednesday's Champions League clash at the Emirates Stadium.

Dutch duo Klaas-Jan Huntelaar and Ibrahim Afellay netted in the final 14 minutes to deal another significant blow to Arsene Wenger's team just days after they crashed to a dismal 1-0 defeat at Premier League strugglers Norwich.