One-time alternate Robin Soderling stepped up to claim the first semi-final spot as the ATP World Tour Finals moved toward the business end while Spain's Rafael Nadal dealt himself out of the competition with a second defeat.
Soderling fulfilled another tennis dream Wednesday with a 7-6 (7-5), 6-1 victory to end the 11-match winning streak of Novak Djokovic.
Russian Nikolay Davydenko left world number two Nadal winless after two matches and out of the running with a 6-1, 7-6 (7-4) result.
Nadal proved unable to earn the 400th win of his career (399-90) and again failed to defeat a fellow top-10 opponent. He is 1-7 against top-10 foes since his May 17 loss to Roger Federer in the Madrid Masters.
His lone top-10 win since came this month over number-nine Jo-Wilfried Tsonga in the quarter-finals of the Paris Masters.
Nadal twice rallied in the second set from a break down, to no avail, losing serve four times in one and three-quarters hours.
Soderling, who gate-crashed the top 10 this season for the first time after knocking Nadal out of the French Open, qualified first for the four Saturday with a perfect 2-0 record and four winning sets.
The Swede entered the eight-man field when Andy Roddick was unable to play due to a knee injury from October.
His last Group B match Friday will now serve as a training session -- but that's not how Soderling sees it.
"I won two matches in straight sets against world number two (Nadal) and number three (Djokovic). I couldn't have asked for anything more," said the Swede. "So far I'm enjoying it a lot. But there's still at least two more matches to go. I hope to do really well in those two, as well."
Djokovic, who claimed three autumn tournament titles in the space of a torrid six weeks in Asia and Europe, admitted that he has been crushed by the relentless schedule of the 11-month season, going down as his strength drained away in his loss to Soderling.
The fatigued world number-three Serb said it all came crashing down on him in East London.
"I didn't enjoy playing today's match, that's for sure. He was serving really well. All credit to him," said Djokovic.
Djokovic had played the most matches of any man this season on the ATP -- 96 -- and lost for only the 19th time this season against 77 victories and five titles, second only to Andy Murray.
Soderling spent just over 90 minutes in earning his victory with 10 aces and three breaks of the Serbian serve.
He struck 31 winners in contrast to just 13 for Djokovic.
"I've only won two matches so far," said Soderling. "It's very good, but there's still more to come."
Djokovic had claimed all five of the pair's previous matches dating back to 2007.
"He has nothing to lose," said the Serb of his conqueror on the day. "He won four straight sets and absolutely deserved to qualify for the semi-finals. I think he's the best player so far in the tournament."