Faith, as anyone will tell you, can move mountains. And in Roger Federer's case, as he demonstrated yesterday in defeating the 6ft 10in challenger Ivo Karlovic, it can also move man-mountains.
Having held his nerve in the face of the Croats much-vaunted, vertiginous serve, the defending champion came through 6-3, 7-6, 7-6 to earn a quarter-final meeting with the only other former champion left in the draw, Lleyton Hewitt.
It was Hewitt, of course, who was the unwilling means of raising Karlovic's profile here last season, when, as defending champion and No 1 seed, he was beaten by the Croatian qualifier in the first round, something which had never happened before in the Open era.
Doubtless the Australian, who won 6-4, 6-2, 4-6, 7-6 against Spain's Carlos Moya yesterday, could have told Federer all about the potential dangers of his match against the tallest player on the men's circuit. Not that Federer would have needed any extra information before taking on Karlovic for the first time - he had been showered with helpful advice and dark warnings about what the man they - whoever they are - call "King Karlo the Great".
"Everyone is talking about this big serve that is unbelievably accurate," Federer, a relative dwarf at 6ft 1in, had said beforehand. "I would like to face it and see what it's like." He seemed to like what he found. Karlovic's monster serve had provided, respectively, 40 and 39 aces in his second and third-round matches. The total he managed against Federer was 14 - not a bad statistic, but hardly one of awesome proportion.
Asked about the difference, he responded, somewhat defensively: "I am not a machine. I also have my ups and downs. And I was playing against Roger, who returns unbelievable."
Credibility was certainly stretched on many occasions as the fluent Swiss adjusted to the deliveries arrowing down from the overcast heavens and, seemingly with an extra flicker of time to choose his spot, drilled them back down either line, his racket flashing like a musketeer's blade.
The tone was set with Karlovic's first serve of the match, which arrived across the net at a speed of 130mph. The Swiss player returned it, proceeded to draw his opponent towards the net during a brief rally, and then, very precisely, lobbed him. How high did this lob have to be? Let's put it this way - it was just as well there was a temporary gap in the steady transit of Heathrow-bound aircraft making their way across the skies of SW19.
Although Federer didn't manage to break the Croat's serve first time out, he did the trick soon afterwards, dabbing the ball precisely around the court to take a 4-2 lead which he converted efficiently into 6-3.
By the time he had completed his victory, rousing an appreciative No 1 court crowd to a voluble crescendo, Federer had maintained his record of not having lost a service game in this year's competition. It was a crucial virtue.
Federer admitted that his pulse rate, normally exerted during activity, had been working overtime during the temporary periods of inactivity when he prepared to serve. "Usually the pulse goes up when you run," he said. "But against him, it's more 'I hope he's not going to have a huge swing at my serve and, you know, I'll be down. Suddenly if I get broken, I will never see that set again.'
"And that's really the scary thing about playing guys like this. You know if you get broken that there's a very big chance that you're going to lose the set. That makes the pulse go up a little bit." Asked if he had prepared for the Karlovic Effect by getting someone to practise serving to him while standing on a chair, Federer replied, with just a trace of bemusement, in the negative.
"It's all about reaction and trying to read his serve," he said. "I knew it was going to come down to that." He is clearly very happy with his form thus far in the tournament, but sensibly aware of the escalating task ahead. "From here on, only tough opponents will come my way. There's many guys around here who have a chance ... Every time I step on the court I'm playing at a very high level. You really need somebody who can play in the very high level, very consistently. So far nobody's been able to do that on grass this year - but it can change very quickly."
After last year's traumatic experience at the hands of Karlovic, Hewitt is only too aware of the wisdom of that statement. But, guess what, he has learned from it.
"I like to think that I'm a better player because of it," he said. "There weren't too many positives at the time. But when I come back a year later I think the memory's obviously there in the first round particularly. Once I got past that hurdle I felt like I really got it out of my mind." Asked if he believed he could beat the man who succeeded him as champion here tomorrow, he replied, guess what, in the affirmative.
"Yeah," he said. "I believe I can beat him. It's going to be an extremely tough match. He's the best player out there at the moment - he's No 1 in our world for a reason and he's going through the draw pretty convincingly at the moment. So I'm the underdog, for sure. But I believe in my ability and I've played well enough against him in the past."
Hewitt is drawing some comfort from the memory of how he defeated Federer in the Davis Cup semi-final, when he came back from two sets and a break down. But, as he went on to point out, the Swiss player has since beaten him in the Australian Open en route to taking the title.
While Federer and Hewitt contemplate what looks like being one of the key matches of this year's tournament, the man seeded one place behind the Swiss champion, Andy Roddick, is preparing to play against the man whose life he helped save in a Rome hotel fire last month, Seng Schalken.
Roddick progressed to the quarters with a 7-5, 6-4, 6-4 over Alexander Popp, the man who might have played for Britain because his mother was born in Wolverhampton, but who actually represents Germany because they got wise to him quicker. Schalken earned his place with a 6-2, 7-5, 3-6, 6-2 win over Vince Spadea of the United States.Reuse content