Murray fought back from a precarious position against Youzhny

The 20-year-old Murray won 6-2 5-7 7-6 to book a fourth final spot of the year, against Fernando Verdasco.

Murray was 5-2 down in the decider but steeled himself to win the next three games, saving a match point on his own serve in the process.

The last two games went with serve before Murray won the tie-break 7-1.

"Of course, the match point was the key moment," Murray said.

"I thought I'd lost... When I won that key (point), he got nervous and made quite a lot of mistakes.

I hurried up, wanted to close it quickly... That does not work with Andy Mikhail Youzhny

"The game at 5-3 when I broke his serve was very important too.

"I hadn't broken him since early in the match but then I hit some good returns, he made a couple of mistakes and the match started to become even again."

Youzhny, who reached 30-0 when serving at 5-3 in the final set, said: "Two good serves and the match could have been in my hands.

"But I hurried up, wanted to close it quickly. That does not work with Andy. A double fault and then I twice hit the net - and the game slipped away."

Fortune had been on Youzhny's side in the second set, when he broke Murray's serve for the first time with the help of a controversial decision.

On set point, Youzhny's shot was clearly out but was ruled in.

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Murray was outraged by the decision but could do little to change the outcome as he had already used both his Hawk-Eye challenges in that set.

Verdasco, the left-handed Spaniard who Murray beat in the Australian Open at the start of the year, was a 6-2 6-3 winner over Croatia's Marin Cilic.

Murray, ranked 16, is 14 places above Verdasco and a win over the Spaniard on Sunday would keep him on course for one of the remaining places in the season-ending Masters Cup.

Next week's Masters Series tournament in Paris is the last chance to earn qualifying points.