CELTIC will have to overhaul a two goal deficit away from home in Europe for the first time in their history in Valencia on Thursday night in order to go through to the last 16 of the Europa League.

Brendan Rodgers’s team goes into the second leg of the last 32 tie at the fabled Mestalla trailing their opponents 2-0 after a disappointing night at Parkhead last Thursday.

The Scottish champions have come from two goals behind to triumph five times in the 57 years they have been involved in continental competition. But they have only progressed to the next stage on four occasions. Read on to find out why.

However, the Parkhead club have never achieved the feat away from home since their first ever European game, ironically against Valencia in Spain, in the Inter-Cities Fairs Cup in 1962.

Here we have a look at all of the times that Celtic upset the odds in Europe when an exit seemed inevitable - and the remarkable events that led to them being denied a place in the next round after producing a sensational comeback.

European Cup, first round
Celtic 4 St Etienne 0, Celtic Park, October 2, 1968

(Celtic win 4-2 aggregate)

Glasgow Times:

THE first occasion Celtic came from two goals down came in the European Cup in 1968. They were beaten 2-0 by St Etienne at the Stade Geoffrey-Guichard in France.

First-half goals from Malian internationalist Salif Keita and France striker Herve Revelli ensured Les Verts (The Greens) won comfortably. The team that had become the first British club to win the tournament the year before looked to be heading out of the tournament after the first round for the second season running.

However, a Tommy Gemmell penalty just before half-time in front of a 73,059 crowd at Parkhead and second-half goals from Jim Craig, Stevie Chalmers and Joe McBride secured a resounding 4-0 triumph in the second leg and a 4-2 aggregate victory.

Jock Stein’s men would go on to reach the quarter-finals that season before losing 1-0 to AC Milan.

READ MORE: Brendan Rodgers adamant Celtic can progress in the Europa League - if they score an early goal in Valencia

UEFA Cup, second round
Celtic 5 Sporting Lisbon 0, November 2, 1983

(Celtic win 5-2 on aggregate)

Glasgow Times:

THE next time Celtic came from two goals behind was against a Sporting Lisbon team managed by one Dr Jo Venglos in the second round of the UEFA Cup in 1983.

Despite staying in the same hotel as the Lisbon Lions had on the eve of their famous win over Inter Milan 16 years earlier in nearby Estoril before the first leg, they slumped to a 2-0 loss after conceding two goals to Rui Jordao.

But the rematch was far more enjoyable. Davie Hay’s men romped to a remarkable 5-0 victory in front of 39,183 fans at Parkhead. Tommy Burns, Tom McAdam, Brian McClair, Murdo MacLeod and Frank McGarvey were all on target.

European Cup Winners’ Cup, second round
Celtic 3 Rapid Vienna 0, Celtic Park, November 7, 1984

(Celtic win 4-3 on aggregate)

Glasgow Times:

IN the European Cup Winners’ Cup the following year the same thing happened. Almost. Celtic lost the first leg of their second round double header to Rapid Vienna 3-1 in Austria. But an away goal from McClair in the second-half gave them a lifeline.

The replay was one of the most extraordinary matches ever played in the East End of Glasgow. Goals from McClair and Murdo MacLeod in the first-half and Tommy Burns in the second ensured David Hay’s men moved into a 4-3 lead in the tie.

But the game descended into ugly scenes when Reinhard Keinast was sent off for punching Burns in his penalty area.

Play was stopped for 15 minutes as Rapid players remonstrated with match officials and protests broke out all over the park. Amid the bedlam, Vienna player Rudolf Weinhofer claimed he had been struck by one of several bottles thrown onto the pitch by Celtic fans.

Weinhofer left the stadium with his head heavily bandaged - but television replays of the incident showed the missile had landed several feet away from him.

Second leg replay Old Trafford
Date December 12, 1984
Result Celtic 0 Rapid Vienna 1 (Rapid Vienna win 4-1 on aggregate).

THE vanquished side appealed to UEFA afterwards and Celtic were fined £4,000 for their fans throwing bottles. But Rapid then appealed that decision and their club doctor somehow managed to convince the governing body that Weinhofer had been hit by a small object that had not been picked up by the cameras.

The match was ordered to be replayed at a venue more than 150 kilometres away. That game took place at Old Trafford and despite an estimated 40,000 Celtic fans travelling down to Manchester Rapid won 1-0 thanks to a goal from Peter Pacult to progress.

Vienna would go on to lose in the final to Everton.

READ MORE: Oliver Burke insists Celtic will be playing for pride in Valencia

UEFA Cup, first round
Celtic 3 Cologne 0, Celtic Park
, September 30, 1992
(Celtic win 3-2 on aggregate)

Glasgow Times:

THE omens didn't look good for Celtic when they lost 2-0 to Bundesliga club Cologne in the first leg of the UEFA Cup first round in 1992.

But a fortnight later they romped to a 3-0 triumph. Goals from Paul McStay and Gerry Creaney in the first-half and John Collins in the second sealed a 3-2 aggregate triumph and made it a memorable night for Liam Brady’s team. It was one of the only European highlights for the Parkhead club during the 1990s.

Champions League, play-off
Celtic 3 Shakhter Karagandy 0, Celtic Park, August 28, 2013

(Celtic win 3-2 on aggregate)

Glasgow Times:

THE modern generation of Celtic fans will still have fond memories of the Champions League play-off against Shakhter Karagandy of Kazakhstan back in 2013.

Neil Lennon’s side had slumped to a 2-0 defeat in the first leg at the Astana Arena after allowing Andrei Finonchenko and Sergey Khizhnichenko to score.

But that set the scene for a remarkable night at Parkhead in the second leg. Kris Commons netted from fully 25 yards out to give the home team a huge lift on the stroke of half-time and Georgios Samaras added a second from close range early in the second-half to level the tie.

With injury-time looming, James Forrest swept home an Anthony Stokes cut back to send the 58,000-strong crowd wild - not to mention his manager who raced down the touchline to celebrate with his players.

"It's the greatest thing I have ever done in football," said Lennon. “This is the greatest night of my footballing life. I have a huge feeling of pride. The hysteria has been disgusting.”

The scenes at the end of that game will be nothing if Celtic pull off the impossible against Valencia tomorrow night.