CINCINNATI (AFP) - World No. 1 Novak Djokovic battled back to beat Ukrainian qualifier Alexandr Dolgopolov 4-6, 7-6 (7/5), 6-2 on Saturday to reach the final of the ATP and WTA Cincinnati Masters.

Djokovic, seeking a 20th ATP Masters 1000 title, will face the winner of the second semi-final between Andy Murray and Roger Federer.

The Serb will be aiming to complete his boxed set of Masters titles, with Cincinnati the only one of the nine elite events missing from his resume.

But with the start of the US Open just nine days away, Djokovic needed on-court treatment from the tournament doctor, and pain-killing medication after he complained of tightness in his abdomen early in the second set.

At that point, the 66th-ranked Dolgopolov - who also had on-court treatment to have his feet taped - was making Djokovic work to stay afloat.

Djokovic gained the upper hand in the second set with a break for a 5-3 lead, but Dolgopolov promptly broke back to push the set to a tiebreak in which the Ukrainian led 3-0 and 5-4 before Djokovic managed to level the match at a set apiece.

From there, Djokovic took control, breaking Dolgopolov twice for a 4-1 lead in the third en route to the victory in two hours and 20 minutes.

The outcome mirrored their most recent prior meeting, in which Djokovic defeated Dolgopolov 6-7 (3/7), 7-5, 6-0 in the round of 16 at the Miami Masters.

To claim a first Cincinnati title, Djokovic will have to get past either six-time champion Federer or Murray - the man who beat the Serb for the title in Montreal last week.

With his run to the Montreal title, Murray grabbed the world number two ranking from Federer, who can reclaim it by lifting the title in Cincinnati.

Such a move would come just in time for the US Open seedings which will be announced next week.