Reuters Sports News Summary

Following is a summary of current sports news briefs.

Stephens stuns ailing Serena, Federer forges on

MELBOURNE (Reuters) - Serena Williams went down smashing rackets and screaming as she bowed out of the Australian Open quarter-finals on Wednesday, hampered by a back injury and beaten in three sets by fellow American Sloane Stephens. The injury robbed Williams of her serve - the most effective weapon in women's tennis - but teenager Stephens will take much credit for holding her nerve to finish off the ailing 15-times grand-slam champion.

No let up for Serena slayer Stephens

MELBOURNE (Reuters) - A day after earning the biggest win of her career, American teenager Sloane Stephens faces another massive challenge when she meets defending champion Victoria Azarenka in the Australian Open semi-finals on Thursday. The 19-year-old stunned the tennis world on Wednesday when she beat 15-times grand slam champion Serena Williams 3-6 7-5 6-4 in the quarter-finals at Melbourne Park.

Knicks unseat Lakers as NBA's most valuable team: Forbes

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Federer survives Tsonga to set date with Murray

MELBOURNE (Reuters) - Roger Federer survived his first major test of the Australian Open on Wednesday, fending off an inspired Jo-Wilfried Tsonga in five enthralling sets to reach his 10th straight semi-final at Melbourne Park. Having not dropped a set in his four lead-in matches, the Swiss maestro was pushed hard by the flamboyant Frenchman, who stormed back into the match twice with some brilliant shot-making under the lights of Rod Laver Arena.

Te'o tells Katie Couric he lied to maintain hoax

NEW YORK (Reuters) - Notre Dame football star Manti Te'o told ABC News' Katie Couric that he had lied to keep up a hoax involving a nonexistent dying girlfriend once he learned he had been duped two days before the Heisman Trophy winner was announced. In a preview of the interview shown on Wednesday on "Good Morning America," Te'o talked about the girlfriend, Lennay Kekua. He mourned her September 12 death from cancer, but it later turned out that she never existed except as part of an online fraud.

Golf: Donald sticks with tried and tested clubs

LONDON (Reuters) - World number three Luke Donald has extended his contract with clubmakers Mizuno as the Englishman seeks to end his wait for a first major title. "I feel as if I am playing as well as ever at this stage in my career. Over the next few years I want to be in a position to win major championships and to continue to improve each year," Donald said in a statement on Wednesday.

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Golf: Rose rues one-shot penalty as Santos leads at Qatar Masters

DOHA (Reuters) - World number four Justin Rose was left bemoaning a penalty on the 17th green as Portugal's Ricardo Santos set the pace with a seven-under-par 65 in the Qatar Masters first round on Wednesday. Englishman Rose, the highest-ranked player in the field, incurred a one-shot penalty when his ball moved as he prepared to tap in for par from 18 inches though he made up for that with a birdie at the par-five 18th for a 68.

Protesting soccer fans disrupt Cairo traffic

CAIRO (Reuters) - Soccer fans obstructed roads and a rail line in Egypt's capital on Wednesday to demand swift punishment of rival supporters and policemen blamed for the deaths of 74 people in a stadium disaster last year. A verdict in the case is due at the weekend, when thousands are expected to mark the second anniversary of Egypt's Arab Spring uprising with street protests against the Islamist-led government.

Motor racing: Pirelli hope for more overtaking and pitstops

MILAN (Reuters) - Pirelli presented its 2013 range of color-coded Formula One tires on Wednesday with the hope that fans would see more overtaking and an end to one-stop races. The sole tire supplier also said it was in talks with Formula One's commercial supremo Bernie Ecclestone to extend its deal beyond this season.