Schalke hit three second-half goals to deal Inter Milan’s hopes of retaining the Champions League a huge blow in the quarter-final first leg in Italy.
Dejan Stankovic gave Inter a first-minute lead with a sublime volley from halfway before Joel Matip equalised.
Diego Milito volleyed Inter in front but Goncalves Edu levelled for Schalke.
A Raul Gonzalez strike and an Andrea Ranocchia own goal made it 4-2, while Inter had Cristian Chivu sent off before a sweet Edu finish made it five.
The tone was set for an enthralling and unpredictable evening’s football after just 27 seconds.
Schalke goalkeeper Manuel Neuer was alert to a probing Esteban Cambiasso long-ball, speeding out of his area and heading the danger away as Milito bore down on goal.
However, Neuer’s clearance to the halfway line was met by Stankovic who showed exquisite technique to direct his volley over the goalkeeper into the net to give the Serie A side a dream start.
Far from being disconcerted, though, the visitors immediately went in search of an equaliser – veteran striker Raul getting in front of a nervy-looking Inter defence to first head wide and then straight at goalkeeper Julio Cesar.
At the other end, Milito teased the Schalke defence inside the area before dinking a cross to the unmarked Wesley Sneijder, who could not rise high enough to test Neuer with his header.
It was all square in the 17th minute when Inter failed to pick up Kyriakos Papadopoulos from a corner. The tall Greek defender’s downward header forced a fine save from Cesar but, in the ensuing scramble, the ball fell kindly to Matip who had the simple task of firing home from inside the six-yard box.
Inter were perhaps unlucky to have a penalty appeal turned down when Milito’s dash on to a through-ball appeared to be checked by Japanese defender Atsuto Uchida.
But Leonardo’s side regained the lead in the 33rd minute when Sneijder chipped a pinpoint ball to the right-hand side of the area allowing Cambiasso to cushion a header into the path of Milito, who volleyed home unmarked from five yards out.
Five minutes before the break, Inter’s defence was breached again, however. Alexander Baumjohann’s measured pass sent Edu racing through on goal. The Brazilian unleashed a right-foot shot which was first deflected by Chivu and then parried by Cesar. At full stretch, though, Edu managed to steer in the rebound from an acute angle with the outside of his left boot.
Dutch playmaker Sneijder had become more of an influence toward the end of the first half, and at the start of the second period he was pulling the strings in his advanced midfield role.
After patient build-up play, Sneijder picked out striker Samuel Eto’o, who cut inside his marker and unleashed a rising goalbound left-foot strike which Neuer expertly palmed away.
Just when it looked like the champions were finding their rhythm, though, 33-year-old striker Raul netted his 70th Champions League goal in the 53rd minute.
An intricate edge-of-area move ended with the increasingly effective Jefferson Farfan sliding a ball through for the former Real Madrid striker, who took one touch to skip away from Ranocchia’s desperate lunge and poke home from close range.
Ranocchia’s night got worse five minutes later when he turned Jose Manuel Jurado’s low cross from the right into his own net just as the on-rushing Edu threatened to meet the centre and finish.
Moments later, Eto’o snatched at a decent chance to fire wildly wide inside the area.
Chivu was sent off by English referee Martin Atkinson in the 62nd minute after, perhaps harshly, being adjudged to have gone through the back of Edu.
The Romanian defender appeared to pull out of the challenge at the last moment, but Edu reacted threatrically and Atkinson did not hesitate to show red.
Jurado hit the post with a 25-yard drive, but with 15 minutes left Edu completed a fine performance with his second goal and his side’s fifth.
Farfan skipped into the Inter penalty area, had an initial shot saved by Cesar before his follow-up from a tight angle came off Ranocchia and on to a post.
The now ragged Italians failed to clear again and Edu spun his marker to fire a sweet left-foot shot past the hapless Cesar and leave Inter’s European dream looking all but over.
For Schalke, lying in mid-table in the Bundesliga, a first-ever Champions League semi-final, against either Chelsea or Manchester United, appears to beckon.