Highlights: Celtic 6-2 St Mirren

Kheredine Idessane
BBC Sport Scotland Senior Reporter

Celtic will face Dunfermline Athletic in next month's Scottish Cup final after a thrilling, eight-goal epic with St Mirren at Hampden was eventually settled by a sensational spell in extra time.

With the match tied at 2-2, four goals in six minutes blew the Paisley side away after they had come from two goals down to force the additional half-hour.

In that additional period, quick goals from the head of substitute Kelechi Iheanacho and the boot of Luke McCowan broke the Buddies' spirit before Iheanacho slammed in a fifth. Extra gloss was added when Sweden international Benjamin Nygren stroked in his 20th goal of an impressive debut season.

It pits manager Martin O'Neill against his former midfield stalwart, Neil Lennon, in a repeat of the 2007 final, which the Pars lost 1-0 in their last appearance in the end of season showpiece.

It all seemed so harsh on a St Mirren side - and their 17-year-old goalkeeper - who fought back superbly after conceding in the first and last minutes of the first half.

Daizen Maeda's quick closing down pounced on an error from goalkeeper Ryan Mullen to give Celtic a dream start after just 57 seconds before a superb Anthony Ralston strike doubled the lead on the stroke of half-time.

Celtic also hit the woodwork through Arne Engels and Yang Hyun-Jun and regretted their inability to kill the game off when Mikael Mandron headed St Mirren back into contention shortly after the break.

His fine, powerful shot in the 91st minute seemed to indicate the tide turning in the Paisley side's favour but the Scottish champions found an extra couple of gears in extra time.

All of this happened after a somewhat chaotic opening spell in which Mullen - deputising for the injured Shamal George - was forced off injured on 14 minutes, meaning a professional debut for teen Grant Tamosevicius. The youngster made a couple of good saves but could do little about Celtic's devastating onslaught in extra time.

The record 42-time winners are through to the final on 23 May but were made to work extremely hard for their place.

Analysis: Celtic blitz eventually overcomes St Mirren

O'Neill had bemoaned a lack of energy in his side in the narrow Scottish Premiership win over St Mirren last week. It was quite the opposite, certainly in the opening stages at Hampden, with a place in the cup final up for grabs.

Celtic hustled and harried the Buddies to distraction, chasing down every ball and forcing the Paisley side to panic at times. The opening goal was a classic example.

One has to admire Celtic's resilience and patience, too. There was no doubt they were the better side in spells in the match, particularly with the goal rush in extra time. Their heads could have sunk when St Mirren equalised but the response will have heartened O'Neill greatly. The team who have won games narrowly of late all of a sudden found half-a-dozen when it mattered most.

For St Mirren, this was a match that started calamitously, rapidly deteriorated, improved considerably before they finally fell away. A proper rollercoaster of a performance.

They rallied superbly from their multiple early setbacks and may well have thought they were on their way to the final when they found an equaliser and plenty of momentum.

Craig McLeish's men deserve great credit for the way in which they dealt with an extremely tricky situation and grabbed a Scottish Cup lifeline through Mandron's mighty double.

But it's Celtic who advance to their 62nd final, where they will be overwhelming favourites to claim a 43rd Scottish Cup against Lennon's Championship promotion-chasers Dunfermline.

Not for the first time, though, there will be concerns that the bar set by their first-half display lowered significantly after the break as they now look to build momentum for the defence of their Premiership crown in the five remaining league games. They can at least take heart after rediscovering their scoring touch.

What they said

Celtic manager Martin O'Neill: "Delighted. Almost had the game won. St Mirren, who were never out of proceedings and showed a lot of quality themselves, got the equaliser. It's a matter of trying to win again and so we come up big in the first period of extra time. It was great for us, really great.

"James Forrest coming on, making the first goal, Iheanacho scoring, naturally a major turning point in the game just when St Mirren had gained the advantage just by scoring late on in proceedings going into extra time. For us to score so quickly was a blow to them and obviously a major boost to us.

"We took the goals brilliantly and it was a joy; joy, from our viewpoint. I couldn't be more pleased with the team, really, considering that they could've crumbled just in extra time."

St Mirren manager Craig McLeish: "I'm so proud of the group and how they performed throughout the day. To come back from the set-backs that we had early on in the game like losing a goalkeeper early on, losing the goal in the manner in which we did early on, to fight back from that and the fans pulled us through.

"Second-half performance was up there with the best since I've been in charge of the group. We thought we were in a really good place going into extra time. We made some changes that probably helped us get back into the game. We end up with a lot of attacking players on the pitch.

"We change our shape as well so taking those risks help us get to extra time and then they maybe expose us a little bit there, the quality that Celtic bring on the pitch then takes its toll and they hurt us."

What's next for these teams

Defending champions Celtic, who are third in the table, begin their post-split programme in the Scottish Premiership at home to Falkirk on Saturday (17:30 BST).

Tenth-placed St Mirren host bottom side Livingston on Saturday (15:00).