Andy Murray defeated by Federico Delbonis in three sets at Indian Wells

Andy Murray suffered a shock defeat against world No 53 Federico Delbonis in the third round at Indian Wells.

The British No 1 had a frustrating time from the outset and lost a decisive tie-set to an inspired Delbonis, who completed a 6-4 4-6 7-6 victory.

 Murray appeared to have recovered from dropping the opening set and was leading 4-1 in the third until Delbonis found a second wind to earn the biggest result of his career.

Murray, who has only ever got beyond the last four of this tournament once (2009), said: "I think it's just the conditions I have just struggled with here throughout my career.

"I have never really felt that I played my best tennis here. I have tried and had many different preparations where I've got here early and spent a lot of time on the courts, and sometimes I arrive later, like this time from Davis Cup.

 "Obviously it takes time to get used to new conditions regardless of where it is, but I have just never really found a way to get comfortable here throughout my career. It's a shame.

"I changed stringing my racquets like four or five pounds tighter than I was at the Davis Cup, which is significant. Really the tightest I have strung throughout the whole year would be at this event, and I still feel like I can't really go for my shots.

"I feel like when I do, I make mistakes. But even you look in the tie-break I missed a couple of backhands long, and then also a couple of balls in the bottom of the net. It just never quite worked out for me here."

 An out-of-sorts Murray struggled to get going in the opening exchanges, holding his serve three times consecutively but rarely with the vigour that might have been expected against a lower-ranked opponent.

Left-handed Delbonis hung around in the early stages and, after forcing deuce with Murray on serve at 3-3, took advantage of the Brit's restlessness at his own performance to snatch a break. The Argentine then had the calmness to hold his own serve twice more and take the first set in 42 minutes.

Murray even found humour at his own shortcomings in the second set, sarcastically laughing at himself after conceding break point, although he swiftly saved it. He struggled through his own service game before edging 2-1 ahead.

 The struggling Murray hit a stunning defensive shot that turned into a winner but still needed to save break point before forcing his own break to win the set.

It seemed Delbonis' resistance had faltered as Murray secured a quick break and went 4-1 up yet the plucky South American forced the set to go to 5-5. The rollercoaster set then saw both men break to force a tie-breaker.

The tie-break went neck-and-neck until a Murray error put him 3-5 behind and resulted in a racket smash. Delbonis earned three match points and completed the upset at the first attempt, setting up a last-16 clash with either Gael Monfils or Albert Ramos-Vinolas.