When Shaun Murphy trudged off the Crucible floor for the last interval of his World Snooker Championship semi-final, trailing 15-13, his dreams of a second world title were on the brink of collapse . Just two frames away from defeat, against the grittiest of opponents in 50-year-old, four-time world champion John Higgins , Murphy required something special. And that’s exactly what he delivered. A sublime break of 105, his third century of the session, narrowed the gap to one before an equally clinical break of 78 levelled the match once more. From 13-11 down overnight, he had already fought back to 13-13 with back-to-back tons in the blink of an eye and now he had eradicated a 15-13 deficit to turn a four-session match into a best-of-three shootout for a place in the world final.…