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.