Did Novak Djokovic go too far?

KEY BISCAYNE, Fla. -- Tuesday, in a magnanimous gesture of sportsmanship, Novak Djokovic gave Tommy Robredo a point he didn't have to.

"For me, it's something that is part of the sport and fair play," he explained. "I expect everybody else to do the same."

But on Wednesday against Andy Murray -- a man he has played in four Grand Slam singles finals in the past three years -- Djokovic wasn't feeling so generous. With Murray serving the first point at 5-6, Djokovic hit a forehand volley with his racket clearly extended across the net by a foot or so when impact occurred -- technically a point for Murray. And yet, Djokovic conceded nothing. When chair umpire Damian Steiner declined to intervene, Murray sort of lost his mind, and immediately thereafter, his composure.

After jawing heatedly with Steiner, Murray swiftly lost the next three points and the set with it. That foreshadowed events soon to come. Ultimately, the match went to Djokovic, 7-5, 6-3.

"He got upset and he made couple of unforced errors," Djokovic said. "I was just trying to play point by point, make him play as much as I can, change the pace of the ball. He made three unforced errors and the set was gone.

"I think he can tell you better if that influenced his game and his set and his, you know, mental strength."

Murray lost the last two games at love -- and 12 straight points overall -- and finished with 32 unforced errors and only 17 winners. He had five double faults, two in the pivotal sixth game of the second set.

Afterward, Murray declined to blame Djokovic.

"For me, it's impossible to tell from where I was, but I knew it was close," Murray said later. "So that's why I went and asked Novak, and he told me he was over the net. That was it."

And what did the umpire say when queried?

"He said, 'Yes, he was over the net, but he was in line with the net,' Murray said, "so I didn't really -- I didn't understand really."

The replay clearly showed Djokovic was over.

"If it was over the net, it was over the net, and I was right to complain and that's it," Murray said. "I was correct. And then, yeah, I mean, it maybe had a slight bearing on that game, but I was still up a break in the second set."

You could see this one coming from, well, Orlando at least.

"Look, I'm going to be completely honest with you," Djokovic said. "I did pass the net with my racket, and I told Andy that. I told him that I did not touch the net. My bad. I thought that it's allowed, to cross the racquet on his side without touching the net. That's why I thought I won the point.

"I did not know that the rule is that I'm not allowed to cross the net. That's all I can say."

Djokovic has been in fine form while Murray has struggled after undergoing back surgery late last year. And then he lost his coach, Ivan Lendl, before the tournament. Murray claimed it was a mutual parting, but one of the British journalists who covers Murray for a living said he seemed "gutted" at his first news conference here.

Murray's inability to flush that faux pas away at the end of the first set eerily echoed the Scot's pre-Lendl cranky demeanor. He has always seemed to thrive on the support of his box, and Lendl, who suggested he might attend the match, wasn't in it.

It was strange, because Murray was playing on home turf. He has a condominium in downtown Miami and often practices on the stadium court here. Just earlier this month, the two athletes who have known each other since juniors and practiced together played a friendly exhibition at Madison Square Garden.

Djokovic now has a 12-8 head-to-head advantage over the defending Miami champion and has won four of five.

More troubling is this little nugget: Murray hasn't beaten a top-10 player since last July, when he hammered a tired Djokovic 6-4, 7-5, 6-4 in the Wimbledon final.

Djokovic faces the winner of the night match between Roger Federer and Kei Nishikori in the semifinals on Friday.

As a sidebar to the controversy, the back, apparently, remains an issue.

Murray had surgery (the specific nature of which he has yet to disclose) after last year's US Open and missed the rest of the season. There were times during his fourth-round match with Jo-Wilfried Tsonga that he grimaced and grabbed his back on a few occasions. Against Djokovic, there were times when it appeared he wasn't getting a full rotation on his groundstrokes, particularly from the backhand side.

"I have been able to play for the first three months of the year without too many problems and too many setbacks," Murray said. "So if someone had told me after the surgery this is where I would be going into April, it wouldn't be too far from where I would have liked to have been."

And then there is the issue of recently departed Lendl. Murray says the time frame for finding a successor is about six weeks.

Last week, when he announced that he and the eight-time Grand Slam champion were dissolving their student-teacher relationship, Murray was asked if he would miss Lendl.

"I don't know," he began uncertainly. "The Olympics was the first big tournament I won and Ivan wasn't there."

And then he paused.

"Can't replace someone like him," he continued. "It's very hard to replace someone like him. But I would hope that I've learnt enough from him and a way to approach those matches and how to deal with those situations better. Because I have won those matches, so I know how to deal with it better now.

"Yeah, obviously I would still like to have someone like that in my corner in those situations, because he's going to help."

Right now, it appears the reigning Wimbledon champion could use all the help he can get.