If Novak Djokovic wants to win a second Wimbledon title, he'll have to perform better in the final against Roger Federer than in his semifinal Friday.
He admitted as much.
While seven-time champion Federer eased past big-serving Canadian Milos Raonic 6-4 6-4 6-4, top-seed Djokovic struggled to overcome much-hyped Bulgarian Grigor Dimitrov 6-4 3-6 7-6 7-6 in a nonetheless highly memorable encounter.
Not for the quality of tennis, mind you, but for the momentum shifts, some of the unforced errors and the number of slips.
On one occasion, Dimitrov and Djokovic took a tumble at almost the same time and faced each other close to the net, much to the crowd's delight.
For the combatants, the court must have felt like a skating rink.
Maybe playing in front of Maria Sharapova -- Dimitrov's girlfriend -- was just too much for the duo. Sharapova is also friends with Djokovic, though her loyalties weren't divided on Center Court.
"At a certain stage of the match I was frustrated because I again allowed my opponent to come back to the match," Djokovic, referring to his quarterfinal against Marin Cilic, told reporters. "That's something that I definitely cannot allow myself in the finals against Roger."
The conditions weren't easy. It was windy and hot.
But Djokovic was in control, leading by a set and break, and he led by a break in the fourth set before needing to rally from 6-3 down in the tiebreak.
Indeed, when it looked like Dimitrov would force a fifth set, the match resembled last year's Wimbledon semifinal between Djokovic and Juan Martin del Potro.
Djokovic also held the advantage in the fourth set then but lost it and was forced into a fifth, which no doubt affected his display in the finale against Andy Murray.
The silky smooth Federer had no such problems with his footing, his court positioning further up than Djokovic and Dimitrov. Raonic and Dimitrov, part of the younger guard, played in their first grand slam semifinals.
Djokovic hired Boris Becker in the off-season -- the German was one of the best volleyers of his generation -- but the Serb only won 57% of net points Friday. On a first match point in the fourth-set tiebreak, he failed to put away two volleys, temporarily keeping Dimitrov in the affair.
Becker declined an interview request from CNN after the match.
Djokovic put in a worrying display (for his fans at least) Wednesday too, taken to five sets by Cilic. He won the first set against Cilic and had a 9-0 record against the Croatian prior to Wimbledon.
If this was 2011, when Djokovic won three majors, he'd have coasted.
"When Novak is at his best, you think, 'How can anyone beat him?" asked Wally Masur, an Australian tennis analyst who won three titles during his playing days. "But hanging on to his best for long periods of time is something that has really kind of eluded him since he had that brilliant year.
"I don't know why that is. He smoked Cilic in the first set and the next thing you know they're in a dogfight."
And had it not been for a lucky Djokovic shot in the third set, Dimitrov might have advanced to a maiden grand slam final.
Staring at a break point at 3-3, Djokovic didn't hit his backhand down the line cleanly, but it went over the net and gave the speedy Dimitrov no chance.
Dimitrov then imploded in the third-set tiebreak.
What significantly helped Djokovic was hitting 17 aces. Dimitrov's serve, meanwhile, let him down.
At 6-6 in the fourth-set tiebreak, he gifted Djokovic a double fault for a second match point.
Federer, who improved to 9-0 in Wimbledon semifinals, handled Raonic in as routine a fashion as the score suggested.