Nadal leaves London at fresh low after latest defeat

The winner of the first end-of-season championships to be held in London will not be known until tomorrow, but there can be little doubt as to the most significant loser.

Rafael Nadal had arrived here knowing that he could end the Barclays ATP World Tour Finals as world No 1, but instead left with the worst record of all the players in the eight-strong field.

Nadal had already been the first to be eliminated after losing his first two matches in straight sets and the 23-year-old Spaniard made it a hat-trick yesterday when he went down 7-6, 6-3 to Novak Djokovic. It was Nadal's fourth defeat in a row – the last time he had such a run was in 2004, when he was just 17 – and the eighth match in succession against a top-eight player in which he has failed even to win a set.

Djokovic, having won two of his three Group B matches, was hoping to join Roger Federer, Juan Martin del Potro and Robin Soderling in the last four, but was facing an anxious wait before Soderling met Nikolay Davydenko last night. Two players go through to the last four from each group and Davydenko went into the final match of the round-robin phase knowing that a victory would take him through at Djokovic's expense.

Nadal and Djokovic have now played each other 21 times. The Spaniard has won on 14 occasions, but he rarely looked capable of improving that record. Both men looked well short of their best and made a combined total of 72 unforced errors.

Djokovic was playing his 97th match of the year and his weariness was evident. Having broken serve in the fourth game, the Serb wobbled as Nadal fought back to lead 5-4 but held on to win the tie-break 7-5. Nadal had treatment for a back problem after three games of the second set, after which he immediately dropped serve. Djokovic served out for victory, sealing it on his third match point.

After the shambolic scenes on Thursday night, when players and spectators waited long after the final match to learn who had qualified for the semi-finals from Group A, tournament organisers promised yesterday to review their procedures before the event returns here next year.

The confusion, which led to many of the 17,500 crowd leaving the arena not knowing that Andy Murray had been knocked out, was caused after Del Potro beat Roger Federer 6-2, 6-7, 6-3 in the last match in Group A to leave Del Potro, Federer and Murray tied in terms of both matches and sets won. A countback on the percentage of games won in their round-robin matches subsequently decided which two of the three went through.