Fiorentina needed penalties to see off Groningen after a scintillating 2-2 on aggregate.

The Viola started with the advantage of the away goal and knew that their Dutch visitors had to chase the game, but they couldn't have expected such a rollercoaster ride.

Groningen fought to the bitter end and the fans at the Artemio Franchi witnessed a great cup tie.

Coach Cesare Prandelli gave veteran hitman Christian Vieri the nod in attack with Adrian Mutu and Franco Semioli playing in wider positions.

The Gigliati proved that they had no intention of sitting back as Mutu went close with his head after just six minutes.

Riccardo Montolivo was a whisker away from forcing an own goal as his driven strike clipped a defender and finished just the wrong side of the post.

Defender Bruno Silva swung a dangerous ball across, but the whistle went for a push by a Groningen player.

Fiorentina were the more dangerous side and Montolivo was on fire as his strike was parried by Brian Van Loo and Silva did well to stop Mutu putting the rebound away.

It was all Montolivo as the Azzurrini star cut inside and fired into the side netting with nearly half an hour played.

Mutu wasted a good chance as he controlled a delightful ball only to horribly sky his shot, but minutes later he rapped the post from the penalty spot with Van Loo beaten.

The hosts received their first jolt when Markus Berg broke into the box and found Goran Lovre whose effort was narrowly wide.

The game continued at a good pace with both sides taking an attacking approach and Mutu came close again after a one-two with Vieri.

The visitors came out looking like a different side in the second half and Sebastien Frey did well to react and stop a Lovre header after a corner.

After 55 minutes Groningen went ahead through Erik Nevland who took advantage of a fantastic ball from second-half substitute Koen Van de Laak to turn it home for 1-0.

With elimination staring them in the face for the first time, the Viola hit back quickly as Mutu took the ball in the box, turned and lashed it into the corner.

The away goals advantage was over and it was a true cup tie as Frey parried a Nevland header from a Martijn Meerdink free-kick.

Vieri connected with his head, but he couldn't keep a Mario Santana cross down.

Santana was again the danger man as he dribbled to the by-line and forced a corner from Sierra Leone star Gibril Sankoh.

Disaster was averted with seven minutes left on the clock as Frey saved a well-hit effort from Lovre.

The tie went to extra-time and the strain started to show on the hosts as Yevgeny Levchenko's shot was tipped wide by Frey.

Zdravko Kuzmanovic was introduced for a flagging Marco Donadel as the prospect of penalty kicks loomed large.

Giampaolo Pazzini was agonisingly close to being the saviour as Van Loo came too late to claim a Tomas Ujfalusi cross, but his header shaved the post.

The nerves were truly jangling as the ball bobbled around in the Fiorentina box with 11 minutes left, but it was finally hacked away.

With just 60 seconds of play left, Fiorentina were so close to stealing the win, but Van Loo's heroic double save to deny Mutu ensured that it went to spot kicks.

The kicks were taken underneath the Curva Fiesole where the most passionate Viola fans congregate.

Levchenko blazed the opening kick over, while Pazzini kept his nerve to make it advantage Fiorentina.

Van Laak stroked his home, but Montolivo capped his flawless night by keeping the Gigliati ahead.

Lindgren hit the post and Kuzmanovic sent Fiorentina 3-1 ahead, but there was still drama!

Silva scored for Groningen and Santana missed the kick to wrap it up. Lovre made it 3-3, but Mutu just needed to convert his kick to win it.

And the Romanian made no mistake! At 11.45pm local time, Fiorentina finally booked a place in the next round after a titanic struggle that will live long in the memory.

Fiorentina: Frey; Ujfalusi, Gamberini, Kroldrup, Pasqual; Donadel (Kuzmanovic 97), Liverani (Santana 58), Montolivo; Semioli, Mutu, Vieri (Pazzini 80)

Groningen: Van Loo; Silva, Sankoh, Kruiswijk, Stenman; Meerdink, Lindgren, Lovre, Lewlsjenko; Nevland (Kolder 102), Berg (Van de Laak 46)

Ref: Batista (Por)