Substitute Anthony Stokes headed Celtic into the Scottish Cup final as they needed extra time to see off Dundee United in a thrilling 4-3 win at Hampden.
There was barely 80 seconds on the clock when Kris Commons opened the scoring for Celtic for the fourth match running with a superb strike. Mikel Lustig hit the post with a header before a breakaway move saw United grab a 24th minute equaliser through Gary Mackay-Steven.
United edged ahead on the half hour mark through Jon Daly's header but only held their lead for just over a minute before Victor Wanyama nodded Celtic level. Celtic regained their advantage through a freak goal which Commons put in with his chest on the hour mark but Daly directed a superb header past Fraser Forster to haul United back on level terms in the 71st minute.
With the match in extra time Daly came within inches of a hat-trick as he sent a header off the post before Stokes bulleted the winner past Radoslaw Cierzniak in the 104th minute. The win ends a run of three defeats at the national stadium for the Hoops and keeps alive their hopes of clinching a domestic double as they progress to May's final where they will face Hibernian, who themselves needed extra time to defeat Falkirk in a seven-goal thriller on Saturday.
"There is some relief but I'm thrilled and so proud of the players. They've had a monumental season up to now," Celtic manager Neil Lennon said. "I'm glad to get over the line at Hampden for the first time in a while and now we've got a cup final that we need to win."
His Dundee United counterpart said the defeat was difficult to take. "It was disappointing. I thought the players were exceptional and gave everything they had," Jackie McNamara said.