(Photo source: sina.com)
As he almost always does, Federer proved just a little too good, emerging with a 7-6 (7/5), 7-6 (7/4), 7-6 (8/6) victory over the tenacious sixth seed in a match that took almost exactly an hour for each set.
The victory in the 6.9 million-dollar men's and women's hardcourt tournament marked the second straight year that Federer has completed the double in the first two prestigious Masters Series tournaments of the season - at Indian Wells, California, and Miami.
The 24-year-old Swiss improved to 27-1 for the year, a run that included the Australian Open title in January as well as the title in Doha.
The dominant force in the men's game admitted he welcomed the kind of battle offered by Ljubicic as a way to show his ongoing success is deserved.
"I like the challenge," Federer said. "This is very nice, to have such a close match and come through it and show once again that I really belong to the No. 1 position and deserve all these trophies I win.
"Really, I can show in the most important moments how good I am."
For just a moment in the third set, it looked as if Ljubicic might be able to at least slow Federer's progress toward the title, as he broke early and took a 3-1 lead before Federer responded - breaking back to knot the set at 3-3 as they moved on to the tiebreaker that now seemed inevitable.
Again Ljubicic had a chance, earning a set-point at 6-5 in the decider that Federer saved with a service winner.
Two points later, Federer wrapped up the match with a backhand service return that got a little nudge from the netcord.
"I was obviously lucky on match point, but I'm extremely happy the way I played," Federer said. "To do back-to-back Indian Wells and Key Biscayne feels great."
Federer improved to 10-3 over Ljubicic, including their last seven meetings.
"It was just the bigger points he played better," Ljubicic said. "He definitely played more relaxed and more confident than I did.
"On 6-5, set point in the third set (tiebreaker), he comes up with a great, great serve.
"Then on match point he hit the net. In those moments, it's something else that made the difference.
"Straight sets, it's maybe a little hard, but he definitely deserved this win."
Ljubicic made him work for it. The Croatian Davis Cup hero didn't drop a point in his first three service games of the second set.
But Federer forced the chance he needed in the seventh game, when Ljubicic netted a backhand and then fired a forehand wide to give his opponent a double break point at 15-40.
Ljubicic managed to save both, but another backhand into the net gave Federer another opportunity. He took it, running Ljubicic ragged in a long rally that ended with the Croatian knocking a forehand wide to give Federer a 4-3 lead.
Ljubicic, winner of two titles already this year, in Chennai and Zagreb, wasn't about to let Federer parlay the break into a runaway.
He immediately broke back to knot the set at 4-4. Federer had another break chance in the next game, but with Ljubicic helpless at the net the Swiss lofted his passing attempt long.
Ljubicic seized the advantage in the tiebreaker, taking a 4-1 lead before Federer captured the final six points for a two-set advantage.
Federer had pocketed the first set with his sixth ace to close out the tiebreaker after the first set went without a break of serve.
"I wasn't that nervous going into the match today, but then I realized very quickly this is going to turn out to be a tough one," Federer said. "This is more when I started to get a little tense. But I think that's good, too."
In all three tiebreakers, Federer said, he just tried to maintain his poise.
"I believe serve is very important in the breaker, but even if that doesn't work I never panic.
"I think that's the key in the end. You can't panic. You've got to believe in your game, and that comes through confidence and knowing your game to 100 percent. That's what I know about my game, what shot can I hit in what moment and what are the percentages. I think that's sort of what I calculate very good in that very moment, the split second I have."