Andy Murray's seemingly insatiable desire to win Davis Cup matches for Great Britain drove him to a heroic victory over Kei Nishikori and on to a collision course with Novak Djokovic.

The Scot's five-set win over the Japanese number one lasted four hours and 54 minutes and earned the defending champions a place in the quarter-finals for the third straight year.

Murray led by two sets to love but faced losing from that position for the first time in 11 years only to grind out a 7-5 7-6 (8/6) 3-6 4-6 6-3 victory at Birmingham's Barclaycard Arena.

The world number two won all three points for the fourth successive tie - but the odds are against him making that five.

Ever since the draw was made, a clash between the world's top two players has been eagerly awaited, and - if Djokovic follows Murray in committing to the tie - it will take place in Serbia the weekend after Wimbledon.

Britain can, though, take encouragement from Serbia's struggles in Belgrade this weekend against Kazakhstan, where Djokovic had to come from two sets to one down to defeat Mikhail Kukushkin and keep the tie alive before Viktor Troicki completed the comeback.

Murray's match was three minutes shorter than Djokovic's but equalled the longest of his life - the US Open final epic in 2012 against the Serbian that saw Murray win his first grand slam title.

The new father had not played a match for a month prior to this tie and that seemed to catch up with him in the fourth set, but he dug deep into his reserves and found the extra he needed.

He said: "It was one of the longest matches I have ever played in my life. I have been away from the court for five weeks.

"My body is very sore just now. I have put myself through a lot this weekend. I have volunteered for all three days and I really, really wanted to win.

"I maybe wanted to win too much. I was getting frustrated when I wasn't taking opportunities I should have. I deeply cared about today's match and I expect that will stay the same throughout the rounds."

Murray stated before the tie that he was committed to playing in all this year's fixtures having set his sights on a successful defence of the trophy and this was just another example of what a remarkably resilient competitor he is, particularly in the Davis Cup.

Captain Leon Smith was left in awe of Murray's efforts, saying: "I'm pretty much lost for words. He's just a man of steel.

"It's quite astonishing considering Andy hasn't played since the Australian Open final. He's amazing. It's an absolute privilege to sit with him for a match like that and we'll remember that one for a very long time."