DUBAI, United Arab Emirates (AP) Novak Djokovic was again below his best but managed to beat Sergiy Stakhovsky of Ukraine 7-6 (5), 6-3 at the Dubai Championships on Wednesday for his ninth straight win in 2012.

The top-ranked Djokovic looked rusty at times in his opening win against Cedrik-Marcel Stebe, and the victory over Stakhovsky was anything but routine.

Stakhovsky was up 4-3 in the first-set tiebreaker but two costly unforced errors let Djokovic off the hook and the Serb took the set when the 74th-ranked Ukrainian hit a forehand long.

Djokovic had to come from a break down to win the second set and join Andy Murray in the quarterfinals. Murray defeated Marco Chiudinelli of Switzerland 6-3, 6-4.