Newcastle produced a stunning second-half revival to give themselves an excellent chance of reaching the quarter-finals of the UEFA Cup.
After failing to manage a solitary shot on target in an instantly forgettable first half, United then found themselves a goal down to Fernando Correa after 57 minutes.
Totally disjointed and being pulled all over the place by the lively and controlled Real Mallorca side, it looked at that stage just a matter of how many the Spaniards would win by.
But an incredible transformation saw Newcastle rattle in four unanswered goals in just 17 minutes to leave themselves well and truly in the driving seat for the second leg in Palma in a fortnight's time.
In a bad-tempered game, the La Liga strugglers had six players cautioned and Castillo Edu Moya - on loan from Tenerife - dismissed seven minutes from time for two bookable offences.
And to make matters worse for Mallorca, Federico Lussenhoff and David Cortes, two of their cautioned players, will along with Moya, be ruled out of the second leg.
Led by the inspirational Cameroon international Samuel Eto'o, Mallorca dominated the first half with the striker twice going close in the opening minutes.
But it was a mistake by the usually reliable Gary Speed that gifted Mallorca the lead when his misplaced pass went straight to Eto'o whose shot was touched onto the bar by Shay Given only for Correa following up to head in.
Newcastle were all over the place but drew level on 67 minutes when a long ball from Titus Bramble saw Lussenhoff touch the ball under pressure from Alan Shearer to allow Craig Bellamy a clear run at goal.
The little striker kept his composure to fire in his seventh goal of the season and fourth in Europe.
With the crowd firmly behind them, Shearer led from the front and superbly headed in a Laurent Robert corner four minutes later.
Stunned Mallorca were left reeling even further on 74 minutes when their Argentine keeper lost his way and could only divert Robert's 35-yard free-kick into the net via his right foot.
Foolishly Moya was red-carded after 83 minutes after pulling down Shearer and from Robert's right-wing free-kick Bramble volleyed in his third European goal of the season.
The winners of this tie face a last eight date with either Auxerre or one of Sir Bobby Robson's old clubs PSV Eindhoven who came from a goal down to draw 1-1 in France.