Andy Murray
Murray has won two titles since becoming world number one amid two disappointing early exits. Getty Images

Andy Murray was at a loss to explain his second round exit at the BNP Paribas Open to qualifier Vasek Pospisil as his uncertain start to life as world number one continued in Indian Well. The three-time major champion was defeated 6-4 7-6 for the first time in five meetings by the Canadian in one hour and 50 minutes.

The 29-year-old has never won the opening Masters 1000 event of the season, last season being dumped out at the third round and his problems continued just a week on from winning the Dubai Tennis Championships last week. Pospisil beat Kyle Edmund and Dan Evans in the Davis Cup last month, but recorded the biggest win of his career to reach the third round.

Murray was out-of-sorts from the off and was broken four times on his way to a straight sets loss, with former Wimbledon doubles champion Pospisil taking full advantage of the top seed's inept display.

Despite wins at the ATP World Tour Finals and in Dubai, Murray has not had things all his own way since climbing to the top of the ATP standings, having crashed out of the Australian Open at the fourth round and failed early in California.

"I don't know exactly why it is, because in practice I normally play pretty well," said Murray of his lack of success at Indian Wells.

"Some years I've played well. Some years it just hasn't quite happened for me. I don't know exactly why that is. I don't know if it's the conditions. I really don't know why I haven't played my best here over the years.

"He's always played that way, maybe he was doing it better this evening. He was maybe a bit more solid from the back, a bit more consistent from the back of the court. That allows you and gives you more opportunities to come to the net. If you're making mistakes in the first three, four shots of the rally, it's not easy to come in on the correct ball. When you're a little bit more solid, you can be patient and wait for the right shot to come in on."