IT IS amazing how quickly things can change in sport, as Alan McManus found out to his cost at the Betfred World Snooker Championship on Thursday afternoon.

From the elation of securing the unlikeliest of quarter-final victories over John Higgins on Wednesday evening, to being left reeling by a Ding Junhui scoring blitz in their semi-final less than 24 hours later – trailing 6-2 following the first session.

McManus’s 13-11 victory over fellow Scot Higgins saw the 45-year-old become the oldest semi-finalist at Sheffield’s iconic Crucible Theatre since Ray Reardon in 1985.

Following that victory, he jokingly chided the assembled media for labelling him a veteran yet it was Ding – a man 16 years his junior – who looked far more sprightly around the baize on Thursday.

Whether the energy expended and elation felt at reaching the World Championship last-four for the first time since 1993 drained him, only McManus will know, but what is indisputable is that Ding flew out of the blocks to leave the Glaswegian stunned.

The Chinese superstar opened with break of 100 and didn’t let up – following that with knocks of 84, 131 and 62 to lead 4-0 at the mid-session interval in under an hour.

That soon became 5-0 with yet another century and despite the clash being a best-of-33, McManus looked in serious danger of having any chance of victory scuppered within one session.

Yet the world No.29 has always been known for his resiliency and grit – they were big factors in helping him to two World Championship semi-finals and a Masters title in the early 1990s – and he fought back.

It wasn’t always pretty, and he failed to record even a half-century break, but he did enough to get two frames on the board and narrow the gap to 5-2.

However, the Chinese world No.17 had one final shot to fire, making a fourth century break of the afternoon, a majestic 128, to ensure a 6-2 lead.

Making Ding’s performance even more remarkable is the fact that the record for most centuries in a Crucible semi-final is five and McManus will have to find a way to slow the 29-year-old down when they resume at 10am on Friday.

But with relatively low expectations on him, the Scot admitted heading into the clash that his main focus would simply be drinking in every moment of the special occasion at the Crucible.

“At one stage during my match against John Higgins the partition in the middle went up – sometimes you take a moment out there and at that point I did,” said McManus.

“I went and stood against the other table and it was like a church out there. John was at the table and the place was jam-packed and I thought ‘this is where it’s at’.

“I felt dead happy - these days might never come again and no-one knows when that will happen.

“I’m quite a big historian of the game and I enjoy these bricks and this building. It’s a very, very special place for an awful lot of players who have done an awful lot better here than I have.

“To be going out and playing one table is the thrill of the second half of my career.”

McManus was a 300-1 outsider to lift the World Championship trophy before the tournament began and it is fair to say very few expected him to reach the last-four.

It is his first ranking event semi-final in a decade and both he and Ding had to come through three best-of-19 qualifying matches at Pond’s Forge just to reach the Crucible.

It is the first time two qualifiers have met in the last-four at the Worlds since 1978 and even McManus concedes he never expected anything like this to happen.

McManus added: “If someone had said to me at Pond’s Forge a few weeks ago that I would be playing Ding in the semis when he was on the end table and I was over the back, you would just think it’s not going to happen.

“But sport can do strange things sometimes.”

Watch the World Championship LIVE on Eurosport, with Colin Murray and analysis from Jimmy White and Ronnie O’Sullivan.