IT was billed as the battle of the big-name coaches.

But instead the decisive contribution was made by a pair of trainers. Novak Djokovic, the Serb who is working these days with three-time Wimbledon champion Boris Becker, was extended to the full by Marin Cilic, the Croat who has his countryman Goran Ivanisevic in his corner, but a change of footwear at a vital moment prevented any slip-ups from the World No.2.

After completing his 6-1, 3-6, 7-6 (7-5), 6-2, 6-2 win on Court No.1, the 2011 champion will hot foot it into tomorrow's semi-final with Grigor Dimitrov. He will be sure to look out his lucky shoes for the occasion.

"Well, I thought I was slipping, I was falling, and I wasn't really finding the balance in the third set," said Djokovic. "I don't know if it was shoes or socks or whatever. It was very warm. I was sweating a lot, so I wanted to change it. I had a better grip. I had better movement. Maybe it was just mental, but anyway, it worked. If you say they're lucky, then I'll wear them."

Djokovic even took time out to meditate during the fourth set but, billed directly up against the Murray-Dimitrov match on Centre Court, the oohs and aahs mostly drifted across the airwaves from the day's other main distraction. At one point, the whole occasion was becoming so distracted that the Serb had a quiet joke with the chair umpire.

"I think both of us thought it was too much in a way," said Djokovic. "It was kind of strange to feel so much noise coming from the Centre Court. With Andy losing in straight sets, it was obviously a result that all of the stadium, even on Court 1, wanted to see. So I said: 'Let's just stop the match, put it live on the big screen, and watch it till they're done. It's going to be better for all of us'."

While the Serb's partner Jelena Ristic is expecting the couple's first child, still attempting to prove himself the daddy of them all was Roger Federer. The 32-year-old continued his pursuit of a record eighth Wimbledon title with a keenly-contested 3-6, 7-6 (4), 6-4, 6-4 win over his countryman Stan Wawrinka.

Federer, who will reclaim his abandoned ranking as the Swiss No.1 should he reach the final, had lost to Wawrinka in Monte Carlo earlier this year, but held his nerve in a tense second-set tie break to reclaim supremacy. It was incredible to recall that a year ago he was losing in the second round to Sergiy Stakhovsky.

"There was a lot on the line today playing against Stan, you know," said Federer, who along with Wawrinka will contest the Davis Cup semi-finals against Italy in September. "He came out and was crushing the ball, forehand and backhand and even serve, so it was very difficult for me.

"Last year was a major disappointment for me because I always see Wimbledon as one of my main goals of the season. I went back to the practice courts - I didn't have any options left at that point. So I'm happy that one year later I'm back in the semis and with a chance to go further."

As the father of two sets of twins - Myla and Charlene, and Leo and Lennart - Federer revealed he has been chatting with the Serb about how to cope. "He just asked me how life was on the road, how it is to be a dad," said Federer. "So I answered his questions."

This was Wawrinka's third match in so many days and both men agreed that it had caught up on him. "I just know it was tough to play three days in a row, especially when the third is against Roger," said Wawrinka. "You have to be more than 100% ready physically, but mentally also. It cost me a lot of energy at the beginning of the match to play at that level."

Nick Kyrgios was another man whose race was run. The 19-year-old, who vanquished Rafa Nadal, went down 6-7 (4), 6-2, 6-4, 7-6 (4) to the equally big-serving Milos Raonic.

"I think that match had a pretty big impact," said Kyrgios. "I was struggling physically from halfway through the second set but I don't want to take credit away from him."