Murray's new comeback seals Qatar semi-final place

Battle-hardened former world number one Andy Murray staged a defiant new fightback Thursday to beat French qualifier Alexandre Muller to a place in the Qatar Open semi-finals and declared himself ready to win another title before he retires.

On Friday, Murray will now take on Czech powerhitter Jiri Lehecka, 21, who also came back from a set down to overcome top seeded Russian, Andrey Rublev.

Number two seed Felix Auger-Aliassime of Canada is now the tournament favourite after beating Spain's Alejandro Davidovich-Fokina 6-4, 7-6 (7/5) in the day's last match.

Auger will have to beat third seed Danil Medvedev of Russia, who saw off Australian Christopher O'Connell 6-2, 4-6, 7-5. O'Connell needed treatment for an injured foot as he led in the second set but fought on.

Murray lost the first set 4-6 to Muller. The British hero broke his 26-year-old opponent's first serve, then lost two straight service games as the Frenchman threatened an upset.

But Murray produced a masterclass to wrap up the next two 6-1, 6-2 and reach his first ATP semi-final since Stuttgart last June.

He admitted the first set was "physically very challenging" and he had to take "more chances" with his shots to take control.

Murray has had a gruelling time in Doha, where he is a two-time winner but a wild card this year.

He saved three match points before beating Italian Lorenzo Sonego in a tie-break in the first round.

Against fourth seed Alexander Zverev of Germany, Murray was two points from defeat in the deciding third set before surging back.

The Briton said he expects more tough matches this year but is still confident of his chances against the new generation.

"I would like to have quicker matches but sometimes it happens this way and I am sure that is not going to continue throughout the rest of the season."

He said each win made him more confident.

"I would love to win one (title) but I have goals to achieve more than that. I am putting myself in a position now to do that going into the last couple of matches.

"I feel like these last few weeks are a step in the right direction and if I continue to play and compete like I am now, that I will have not just one opportunity to win a title but I will have more chances to do that in this last stage of my career."

His next opponent Lehecka claimed the biggest win of his career in beating world number five Rublev 4-6, 6-4, 6-3.

"The past two months have been very great for me," said Lehecka, who reached the quarter finals at the Australian Open in January.

The world 52, who should rise further with this performance, said he waited to see his opponent's tactics before speeding up his play.

"I just wanted to serve a bit more risky and faster in the second and particularly the third sets."

Murray said he watched some of Lehecka's game and it was "clear that he has a huge game, he serves big".

"I will need to try to find ways to break up his rhythm and make it difficult for him."