Del Potro too good for Murray
Seventh seed Juan Martin Del Potro beat a below-par Andy Murray 6-7 (5/7) 6-3 6-1 in the last eight of the BNP Paribas Open in Indian Wells.
British number one Murray produced some thunderous groundstrokes to take the first set on a tie-breaker, but he fell apart at the start of the second to hand the initiative to his Argentinian opponent.
Although he finally created his first break points of the match in the third set, Murray could not convert and a raft of unforced errors - he made 49 overall - meant Del Potro won at a canter in the end, in two hours and 31 minutes.
This was the first time Murray had faced the Argentinian since beating him in 2009, but he survived a scare in the very first game in Indian Wells.
Del Potro had break points on the Murray serve, but the Scot fought back to deuce before serving out for a 1-0 lead.
Punishing baseline rallies were becoming the order of the day as the first set started to turn into a physical battle and Del Potro was forced to serve to stay in the set at 4-5 and 5-6 - which he did so with a little help from an errant Murray volley.
Third seed Murray threw away a two-mini-break advantage in the tie-breaker, but the Scot won a 43-shot rally on his opponent's serve to bring up two set points and he converted at the second attempt.
Any thoughts Del Potro might wilt, though, soon disappeared as he won nine straight points at the start of the second, including a Murray double fault on break point, on his way to a three-game advantage.
Murray held to love to finally get on the board at 3-1, but he could make no impact on the Del Potro delivery and by the end of the second set, which Del Potro sealed with another dominant hold, had still not created a break point.
That changed in game two of the third set, but Murray could not handle a deep second serve to convert it, and a series of unforced errors in the next game allowed Del Potro three opportunities of his own, the third of which the Argentinian took.
Murray battled back from 40-15 down in game four, and the British number one brought up his second break point with a deep forehand, but again he could not convert.
Murray dumped another forehand into the net to hand Del Potro another break point in game five, then went long to give his opponent the double break, then a pair of double faults in his next service game completed what in the end was a comprehensive defeat.
Murray, who would have gone to number two in the world had he reached the final, told www.atptour.com: "I thought I hit the ball decently throughout the match, but I played better when I needed to in the first set; then obviously hadn't managed to break him in the match.
"I had some chances in the second set, didn't manage to get them. I could've served better and returned better - two pretty important parts of the game.
"He played like someone that's won a lot of matches recently. Especially in the second and third set, when the important moments came he played well."
Novak Djokovic powered his way into the semi-finals as he swatted aside Jo-Wilfried Tsonga with ominous ease.
The world number one did not give his opponent a look-in as he completed a 6-3 6-1 win in less than an hour.
The Serbian broke twice in each set as he tore into the Frenchman's second serve and did not face a single break point on his own serve, extending his winning streak to 22 matches.
In the women's draw, Caroline Wozniacki came from a set and a break down to beat fourth seed Angelique Kerber 2-6 6-4 7-5 and seal a final showdown with Maria Sharapova.
Wozniacki won 10 out of 13 games from 2-0 down in the second, putting her 4- 1 up in the third, but even then things were not simple.
Kerber, who had come out on top in the pair's last three meetings, broke back, but finally succumbed when a clutch of errors proved costly.
"I had a game plan when I went into the match and felt I was doing the right things - I was missing by just a little bit," Wozniacki told www.wtatennis.com.
"Even if I played great shots, she came back and made a good counter and really played well. So I just kept my head cool and tried to hang in there."
Sharapova, meanwhile, was a 6-4 6-3 winner in her all-Russian semi-final with Maria Kirilenko.