Andy Murray fell agonisingly short of remarkable comeback as he was beaten by Jakub Mensik at the Qatar Open.
The 36-year-old trailed 5-2 in the deciding set, Mensik just a game away from victory, but the teenager was twice broken when serving for the match.
Murray could not complete the job in a third tie-break though, as Mensik battled to a 7-6 (6) 6-7 (3) 7-6 (4) win, in a marathon encounter that lasted three hours and 23 minutes.
The Briton ended a six-match losing streak on Tuesday as he got the better of Alexandre Muller, but he was unable to make it back-to-back wins for the first time since August last year.
Murray found a break when Menisk was serving for the opening set, scrapping to take it to a tie-break which brought huge frustration for the three-time grand slam champion.
He brought up two set points and looked certain to need just one, but netted a simple volley and it proved to be a defining moment. Murray lost four points in a row to gift Mensik a set lead.
Neither player could find a break in the second set, as a tie-break was once again required. Murray took a 4-0 and this time there were no slip-ups as he forced a decider.
His level dropped, as Mensik broke in the first game and then made it a double break to lead 5-2 and leave himself two opportunities to serve for the match.
The 18-year-old could not complete the job at the first time of asking and he was broken to love as his second chance also went, as Murray got it back on serve. The pair then exchanged holds to take it to another tie-break.
Murray blinked first, a poor volley allowing Mensik to make a crosscourt pass, and the teenager brought up two match points. He closed the match out, reaching his first ATP Tour quarter-final as Murray was left to reflect on yet another tight match that did not go his way.