THE year of the underdog so nearly claimed another victim. Instead, Wimbledon's all-time top dog proved there is life in the old boy yet.

From Leicester City to Leave, this has been a summer of seismic shocks and it took fours of play before we could say with any certainty that Roger Federer would return a semblance of the natural order to things. While the 17-time Grand Slam winner crashing out of SW19 at the quarter final stage to an ebullient Marin Cilic would hardly have been a sporting upset of Foinavon proportions, particularly by the standards of this year's Wimbledon, he was another thoroughbred who so nearly fell before the final hurdle.

Instead, having saved three match points to record a 6-7 (4), 4-6, 6-3, 7-6 (9), 6-3 win against an inspired opponent, it now looks more likely than ever that this game 34-year-old will go the distance. This act of escapology which booked a record 40th Grand Slam semi-final was completed with an ace, Federer looking heavenward and raising his arms in exultation as though divine inspiration had come into play.

The Swiss legend was the man in the white suit as he strode on court, his dandy white blazer a throwback to days gone by. So much of the history of these championships are also his own back pages and this match will only add to his legend. Thirteen years ago to the day on this very arena, he was outgunning Mark Philippoussis of Australia to claim his first Grand Slam but now he returned, four years after his last Grand Slam title, to chase one last fix at the home of tennis. Winning this match saw him move level with Jimmy Connors in top spot on the list of all-time Wimbledon match winners and should he go on to take the title on Sunday, he would be the oldest winner at SW19 in the open era.

So dazzling has Federer's progress been that it was easy to forget the menacing opponents who still lurked in his path. Marin Cilic was the type of figure who was sure to force him to roll his sleeves up. Seven years his younger, the towering Croat was a Grand Slam winner in his own right, having gunned Federer down in the semi-finals en route to his 2014 US Open win.

Through his first four rounds here, Cilic had sent down 76 aces, approximately 1.5 in every service game. The man responsible for these improvements, 2001 winner Goran Ivanisevic, sat in his players' box. By the end, he was barely able to look.

Twelve months ago, Federer had produced a remarkable semi-final serving day to keep Andy Murray at arms length. Yesterday he had to fend off an onslaught.

Three Cilic service winners in the opening game were a statement of intent, even if Federer answered with two aces of his own. But the Croat was soon getting a better read on the Swiss man's serve than vice versa and too frequently Federer was unable to cope with the pace on his opponent's ground strokes. Cilic's aggression clinched a taut first set tie-break.

When a solitary service break for 3-1 did the trick in the second set, the Swiss army of supporters were apoplectic but eventually the Croat got a little bit over-anxious himself. He carved out three more break points at 3-3 in the third, but couldn't take any, and like an oil tanker this match slowly started to turn. Federer broke immediately and served out to take the set.

Cilic's match points came at the conclusion of that fourth set and how he will rue his failure to take them. With the wind in his sails after edging an epic breaker, Federer didn't need a second invitation when Cilic went into the tramlines to allow him to serve for a semi-final place.

An interested spectator in the closing stages, from the safety of the locker room, was Milos Raonic - even if his own coach John McEnroe had been too busy with commentary duties to see any of his 6?4, 7?5, 5?7, 6?4 quarter final win against Sam Querrey, Novak Djokovic's tormentor-in-chief. Federer met Raonic in a Wimbledon semi-final two years ago and he will do again tomorrow against the new, improved version of the Canadian. Raonic said he had arrived in SW19 with one goal in mind. Winning it.

Another man with designs on this trophy is Tomas Berdych, the Czech player a surprisingly comfortable 7-6(4), 6-3, 6-2 winner against the fast-improving young Frenchman, Lucas Pouille. Let's hope for the Scot's sake that the year of the underdog has done its worst.