Murray double-faulted with victory in sight against Ancic
Andy Murray wasted two match points in a second-round loss to Mario Ancic at the Sony Ericsson Open in Miami.
The Briton was broken early in the first set by the world number 63 but hit back before handing a 6-2 2-6 7-6 (9-7) victory to the Croatian.
Murray took control of the second set, taking the fourth and eighth games.
But in the final-set tie-break, Ancic - serving at 4-6 - saved one match point before Murray hit a double-fault on his second match point on route to defeat.
"That was just a bad serve," said the Scot, who had a bye in the first round.
"It was the first time on tour that I've lost a match when I've had match points so that's pretty disappointing."
Meanwhile, Roger Federer's form continues to improve after the world number one beat Frenchman Gael Monfils 6-3 6-4 in an entertaining second-round match.
I was pretty lucky. I didn't even see it when I hit it
The top seed, who had glandular fever earlier in the season, did not lose his serve despite giving the world number 65 seven break-point chances.
"I tried to play in an aggressive way," said Federer. "I couldn't really chip and charge the way I wanted to do because he's improved his second serve. I played well on the big points."
Spain's David Ferrer lost 6-4 7-5 to Thomas Johansson, while Andy Roddick was made to work for his 5-7 6-2 6-4 win over qualifier Viktor Troicki.
The Serbian was serving at 4-5 in the final set, but Roddick hit a magnificent crosscourt forehand on the line in the first point of the game and four points later broke serve to win the match.
"I was pretty lucky," said the American. "I didn't even see it when I hit it.
"I heard people yell and scream afterwards and I figured that was a good thing. As far as freak show trick shots, that's up there. You don't hit shots like that every day."
In the women's event, second seed Ana Ivanovic eased past France's Emilie Loit with a 6-1 6-2 victory.
Jelena Jankovic squeezed past Sofia Arvidsson 6-7 6-2 7-6.
The fourth seed came back from 5-1 down in the third set and saved five match points in the final tie-break to beat the Swede.
Lindsay Davenport also progressed with a 6-2 6-1 victory over Camille Pin of France.
The American, who was competing at the Sony Ericsson Open for the first time in five years, said: "I would never have thought that five years ago would have been my last time I played here.
"But I didn't play for a couple of years, got injured, was pregnant. Just a lot of things got in the way."