A try two minutes from time from Great Britain centre Gary Connolly clinched a nailbiting victory over Castleford and brought Wigan their first Challenge Cup final appearance for four years.

The Warriors were clinging to a tenuous six-point lead for most of a tense second half before Connolly forced his way over from close range to earn his side a trip to Murrayfield on April 27.

The Warriors will meet the winners of tomorrow's second semi between St Helens and Leeds in Edinburgh, but will surely not face a more difficult test than today.

Coach Stuart Raper, under fire after an inauspicious start to the season, was more relieved than delighted at the conclusion of a match which, after a fast and furious first 60 minutes, proved as much a test of stamina as skill.

For Castleford, who had given their all in a tremendous game, the final scenes were reminiscent of their heart-breaking semi-final defeat by London Broncos at the same Headingley venue three years earlier.

They overcame a jittery opening but made a nonsense of their 20-1 odds by storming into a 10-8 lead with some inspired attacking play based around the storming running of man of the match Michael Smith and creative half-backs Danny Orr and Mitch Healey.

Wigan, lacking three regulars through injury and illness, raced into an 8-0 lead inside 12 minutes after dominating the opening exchanges largely through the prompting of scrum-half Adrian Lam.

Full-back Kris Radlinski was denied a try by a high bounce of the ball after Lam had split the Tigers defence wide open but Wigan displayed clinical finishing moments later to score the first try.

Kiwi Test prop Craig Smith brushed off the attempted challenge of Dale Fritz inside his own half and offloaded superbly from the subsequent tackle to get Lam into space and hooker Terry Newton was up in support to touch down.

Andy Farrell kicked the conversion and stretched his side's lead with a penalty after Dean Sampson was pulled up for interference.

But once Castleford found their composure, they began to create all sorts of problems for the Cup favourites.

Second rower Smith, one of the most improved forwards of Super League, powered his way over on 15 minutes after Orr had slipped the ball from a two-man tackle and Wayne Bartrim added the goal to make it 8-6.

Bartrim then went off with a shoulder injury and Wigan lost winger Brett Dallas for a spell after he clashed heads pulling off a try-saving tackle on Castleford's former Wigan centre Andy Johnson.

Wigan, starved of possession, were clearly rocking at that stage and, when Newton gifted the Tigers the ball by fumbling deep inside his own half, the Yorkshiremen made them pay.

Loose forward Ryan Hudson took a pass from Orr and tore through the tackle of Connolly to touch down for his side's second try, although deputy marksman Orr missed with the relatively easy conversion.

Castleford piled on the pressure with a successful 40-20 kick from Healey but the Australian undid his good work by sending out a loose pass which was scooped up by Wigan centre David Hodgson 10 metres from his own line.

He went 50 metres before offloading to the supporting Dallas who, fresh from the treatment table, sprinted the remaining 40 metres for a glorious try, which Farrell improved.

The second half continued at the same frantic pace and Castleford delighted their big following with a bewildering passage of play in which they kept the ball alive in breathtaking fashion.

Play swung from end to end but defences held sway until Connolly came up with that last-gasp winner.