Djokovic, the World No 2 beat seventh-ranked Berdych 6-4, 7-6 (7/5), 6-2 in two hours and 41 minutes for his 24th victory in a row. Serbia’s Dusan Lajovic was to take on Radek Stepanek of the Czech Republic in the decisive fifth rubber on the hardcourts of a sold-out Belgrade Arena at the time of going to press.
Propelled by a noisy home crowd, Djokovic relied on his serve in the first set, while Berdych tried to indulge him in long exchanges, combining a fast forehand with a wicked sliced backhand.
Both being fast servers, they had six aces each at the end of the first set, but Djokovic’s play was slightly more precise, earning him ten break points against none for Berdych.
Djokovic capitalised on the tenth one he had in game ten, converting his fourth set point for a 6-4 lead after an hour. In the second set, both held on to their serves safely until the ninth game nine in which Djokovic offered two break points, throwing his racquet in disappointment before hanging on.
The racquet did not survive the subsequent tie-break but Djokovic shook off his frustration in time to win 7-6 (7/5) in over an hour.
In the third set, Berdych started to accumulate the errors, offering two breaks to Djokovic who held on to his serve for a 6-2 win, putting the 2010 champions Serbia level with the visitors.
Serbia now depend on Lajovic, the World No 117, who replaced Janko Tipsarevic, out with an injury.