A last-minute Craig Beattie penalty on Sunday sent Hearts into the Scottish Cup final and a meeting with Edinburgh rivals Hibernian, as they defeated holders Celtic 2-1 in dramatic fashion at Hampden.
After a goalless first half, Jambos substitute Beattie set up Rudi Skacel to fire home the opener in the 47th minute.
Celtic had countless opportunities to equalise, with South Korean international Ki Sung-Yeung twice hitting the post with headers before Gary Hooper nodded home an 86th minute equaliser.
With extra-time looming, referee Euan Norris pointed to the spot in the 90th minute when a Marius Zaliukas shot struck Joe Ledley on the arm and Beattie stepped up to drill the ball past Fraser Forster.
League champions Celtic were denied a penalty in stoppage time when Andy Webster appeared to handle in the box, which prompted Celtic manager Neil Lennon to angrily confront the referee at full-time.
The win means Hearts will face Edinburgh rivals Hibernian in May's final -- the first time the sides will have contested the Scottish Cup final since 1896.
Celtic coach Alan Thompson was furious at the penalty decisions.
"I think they are very similar and if he gives one at one end then he has to give the one at the other end," said Thompson, who denied his side were suffering a hangover from the last weekend's title celebrations.
"Yes, they have struck their hands but was it deliberate in both instances? No, I don't think so. It's just inconsistency."
Hearts manager Paulo Sergio said he was proud of his players.
"I am very happy and it's a great moment for us. We didn't beat a poor team, we beat the champions of Scotland that have a great squad, great technical staff and great manager," he said.
"For me to play Hibs in the final is the same as playing any other team but when the time comes we will be ready for them."
Hearts were handed several chances to lead in the opening minutes but failed to capitalise but it was Celtic who should have had the lead on the stroke of half-time when Mikael Lustig's cross found its way over to Ki Sung-Yeung at the far post.
But the South Korean sent his diving header crashing off the post from four yards out.
Beattie replaced Scott Robinson at the break and made an instant impact when he set up the opener with just over a minute gone.
Black picked out the former Celtic forward with a pass and he knocked it into the path of Skacel who took it past Forster before slamming the ball into the roof of the net.
Celtic had a chance to instantly reply but after a good first touch Ki's sent his shot whistling over the bar.
Black then played a quick free-kick to Skacel and Forster had to scramble to push his dipping swerving shot from 25 yards round the post.
Hearts came close to a second when Beattie was given space to run at the retreating Celtic defence and fizz a shot inches wide of the post. Substitute Georgios Samaras, on for Anthony Stokes, then sent a header over the bar, as chances fell at both ends.
It was Celtic who should have equalised in the 82nd minute, though, when Commons found Ki unmarked at the back post with a free-kick but, in a carbon copy of his effort at the end of the first half, the South Korean hit the post with his header.
Celtic grabbed a late leveller through Hooper who headed home from close range after getting on the end of Mulgrew's cross.
Hearts were awarded a 90th minute penalty in controversial fashion when Zaliukas' shot struck Ledley on the arm from close range and former Hoops player Beattie drilled the ball into the net to start the celebrations amongst the Hearts support.