MASTERS CUP, Shanghai:
Dates: 9-16 November Starts: 0600/1000 GMT daily Coverage: Live on Sky Sports; live text commentaries on BBC Sport website; every match live on Radio 5 Live sports extra
Davydenko reached the Masters Cup semi-finals for the first time since 2005
Nikolay Davydenko swept past Juan Martin del Potro 6-3 6-2 to book his place in the Masters Cup semi-finals.
With a win apiece in the Gold Group, there was all to play for and the pair swapped breaks in a sluggish first set.
But Davydenko soon took control, breaking Del Potro again to take the opener before a double break in the second saw him stroll to victory.
Novak Djokovic advanced as the group winner though he lost his final game 1-6 7-5 6-1 to Jo-Wilfried Tsonga.
The semi-final line-up in Shanghai will be completed on Friday when Andy Murray takes on Roger Federer and Gilles Simon faces late replacement Radek Stepanek in the final Red Group matches.
Murray has already booked his place in the last four after the Scot notched up victories over Andy Roddick, who later withdrew from the tournament because of injury, and Simon.
Federer must beat Murray to advance, while a defeat for the four-time Masters Cup winner would hand Simon a place in the last four regardless of his result against Stepanek.
Davydenko was playing in the season-ending Masters Cup for the fourth consecutive season and he used all his experience to see off his 20-year-old opponent.
The Russian was relentless as the pair traded shots from the baseline, breaking Del Potro at 3-1 in the opening set.
The Argentine, who has risen from number 50 to eight in the world rankings this year, relied on a slice of luck at the net cord to help him break back at 4-3.
But from then on it was one-way traffic, Davydenko unleashed another flurry of powerful forehands to break again at 5-3 as Del Potro's serve deserted him.
The Russian comfortably served out the set and raced through the second, winning five straight games, before serving out the match to love.
Maybe it was difficult to stay concentrated because Djokovic is qualified and he has to think about the next match
Del Potro, who is suffering with a toe injury, was let down by his inconsistent first serve and will now return to Argentina for the Davis Cup final against Spain, which starts on 21 November.
"I feel great after reaching the semi-finals. I had a chance in my last match against Djokovic, but I didn't take it and today was my last chance to reach the semi-finals," said Davydenko.
"We had a lot of long rallies and Del Potro was nervous which contributed to him losing the first set.
"In the second he lost his concentration and made more mistakes and that's why I had more chances."
Even though there was nothing at stake - apart from a $100,000 cheque for the winner - Tsonga and Djokovic served up the match of the day in Shanghai.
The Serbian world number three was in dazzling form as he rattled through the first set in 25 minutes, breaking Tsonga twice with a fine array of attacking groundstrokes.
But the Frenchman rallied in the second set, matching Djokovic from the baseline, and breaking him at 7-5 as Djokovic crumbled with four unforced errors.
The Frenchman was on a roll and broke twice in the decisive set, flicking a lobbed winner on match point.
"He was better than me in the first two sets, but I took the second one. It was daylight robbery!" Tsonga said.
"And then for him maybe it was difficult to stay concentrated because he's qualified and he has to think about the next match."
Djokovic, who beat Tsonga in the final of the Australian Open, added: "Every match is difficult and you've got to give your best to win.
"He's a good player, an interesting player, plays with a lot of emotion. He deserved to win today.
"I made some unforced errors but the most important thing is that I'm through."