The Serb, looking to bounce back from defeat to Roger Federer on Tuesday (November 17), needed to win just one set to qualify and triumphed in his final group match 6-3, 7-5.

Djokovic clinched the set he required after 42 minutes, despite his Czech opponent managing to recover from an early break of serve.

Berdych fought back from a break down once more in the second set, but Djokovic broke for the fourth time at 5-5 and saw out the contest.

"I just waited for a game with more second-serve opportunities and that's what happened at 5-5," said Djokovic, who extended his head-to-head record against Berdych to 21-2, including an 18-0 mark on hard courts. 

"It was a solid performance, I think.

"We both can have done better.

"It's been a long year and we did our best."

Djokovic’s semi-final opponent on Saturday (November 21) is Rafael Nadal, who faces fellow Spaniard David Ferrer in their final round-robin match tomorrow.

"Rafa has another match tomorrow and I'm going to watch that a little bit with my team and prepare," said Djokovic.

"Hopefully I'll be able to perform at my best because that's what's needed to win against him."

Earlier, group winner Federer maintained his 100 per cent record with a 7-5, 4-6, 6-4 victory over Kei Nishikori.

The 17-time Grand Slam champion was broken twice consecutively in the first set before taking it in the 12th game. 

He went on to establish a 4-1 lead in the second, but ended up losing the set after his Japanese counterpart rattled off five games in a row to level the match.

Federer built another 4-1 advantage in the final set, and despite Nishikori coming back again to level at 4-4, it ultimately proved to be to no avail. 

"It was extremely difficult," said the Swiss third seed. 

"It was a good match, with more breaks than we are used to.

"Kei is a very good returner, especially on the second serve.

"It was a very physical match, but I enjoyed it."

Federer’s opponent in the last four will be either compatriot Stan Wawrinka or Great Britain’s Andy Murray, who play for the remaining semi-final spot tomorrow.



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