Welcome to our LIVE coverage of Djokovic/Tipsarevic. We're underway in Dubai.

Quick, there's still time to join us for the fourth and final last-eight encounter:

DJOKOVIC 6-1 7-6 - MATCH - Ace from Tipsarevic opens the tie-break scoring en route to racing into a 3-0 and then 4-1 advantage. Djokovic pulls one back ahead of the two changing ends, before clawing his way to 4-4 and again for five and six apiece. The champ finall moves ahead in the tie-break after escaping the set point to squeak the second set and advance to the semi-finals!

DJOKOVIC 6-1 6-6 - A great ovation from the crowd as Tipsarevic goes 30-15 ahead against the grain in some style, but has to fight for deuce after Djokovic takes the resulting two points. On the first advantage, Djokovic has to call for a replay to have his forehand proven as in, forcing the tie-break.

DJOKOVIC 6-1 5-6 - Impressively, Tipsarevic returns fire with a sweep of his own for game eleven.

DJOKOVIC 6-1 5-5 - Unfortunately for Tipsarevic, he's still unable to find that first break of the match which would have made it 1-1 in sets. Djokovic claims game ten love-service.

DJOKOVIC 6-1 4-5 - Tipsarevic powers into a 30-love lead before an errant long shot paves the way for Djokovic to tie the score. The underdog rallies, however, and re-takes control of the game to move 5-4 ahead.

DJOKOVIC 6-1 4-4 - Still nothing between the two Serbs in the second set as Djokovic cruises to a game-15. He remains potentially one break away from a place in the semi-finals.

DJOKOVIC 6-1 3-4 - Tipsarevic continues his stubborn pursuit of a set-leveller, edging the seventh game from deuce.

DJOKOVIC 6-1 3-3 - It becomes six games in this set without a break in service as the top seed levels once more.

DJOKOVIC 6-1 2-3 - From 30-30, Tipsarevic outs before hitting a great ace to deuce. From there, he takes the first advantage to continue his hold on service.

DJOKOVIC 6-1 2-2 - A dispute on an out from Tipsarevic, 40-30 down, shows the right call was indeed made and he is unable to break the serve of Djokovic once more.

DJOKOVIC 6-1 1-2 - Tipsarevic holds off a fightback at 30-0 and 40-15 to move back into the lead game-30.

DJOKOVIC 6-1 1-1 - Tipsarevic provokes a strong response from the crowd as he pegs Djokovic back with some spirited tennis at 15 and 30, but a net in a long subsequent exchange and a cracking ace allow the champ to tie the set.

DJOKOVIC 6-1 0-1 - A good, not to mention important, response from Tipsarevic as he holds off Djokovic to take the first battle of the second set game-30.

DJOKOVIC 6-1 - SET - Another game-15 secures set one at a relative canter for the favourite. Tipsarevic will have to step it up to come from behind against the title holder now.

DJOKOVIC 5-1 - BREAK - Djokovic comes back from 30 down to break serve for the second time in the set, a set it now looks impossible to take away from him.

DJOKOVIC 4-1 - The champ's tail is up early doors, and his stronghold on the first set stretches to three with an assured game-15 performance.

DJOKOVIC 3-1 - BREAK - Back-and-forth game saw Tipsarevic on the verge of having his serve broken before forcing deuce, before eventually succumbing and going two games behind.

DJOKOVIC 2-1 - Love service from Djokovic takes the third game at a canter.

DJOKOVIC 1-1: Tipsarevic holds his own first serve to level the scores at one game apiece.