Sir Andy Murray reached the Qatar Open quarter-finals with a battling 7-6 (8-6) 7-5 win over Austrian Gerald Melzer.
World number 68 Melzer produced a gutsy display, saving eight first-set points before eventually succumbing to the world number one in the tie-break.
The Austrian broke as Murray served for the match at 5-4 but the Scot won the next two games and will next play world number 44 Nicolas Almagro of Spain.
Murray extended his career-best winning streak in competitive matches to 26.
He paid tribute to Melzer, saying: “He played great tennis and dominated large parts of the match. If he plays like this again this year he’ll move higher and higher up the rankings.
“I played pretty good. The depth in men’s tennis is great right now.”
Earlier, world number two Novak Djokovic defeated Horacio Zeballos 6-3 6-4.
After shaking hands at the end of the contest the Argentine asked for a selfie with the Serb 12-time Grand Slam champion.
“That was the first time that I ever had this kind of experience in my career,” Djokovic said. “So, Horacio, well done. Very original.”
Meanwhile, Roger Federer was defeated by German teenager Alexander Zverev at the mixed teams Hopman Cup in Perth.
The Swiss 17-time Grand Slam winner lost 7-6 (7-1) 6-7 (4-7) 7-6 (7-4) in two hours and 30 minutes in a match of high quality.
The tournament in Australia is the 35-year-old’s first after a six-month knee injury lay-off.