67' Ryan Giggs
69' Wayne RooneyThere's still a second leg to come before the manager and anybody else will be thinking of planning for Wembley but, in truth, only Manuel Neuer's brilliance saved his side from an embarrassing scoreline.
Neuer defied United virtually single-handedly before two quickfire goals - by Ryan Giggs and Wayne Rooney - ensured justice was done. Rooney was the provider for Giggs' opener and then found the net himself after cunning play by strike partner Javier Hernandez.
Sir Alex Ferguson opted for a 4-4-2 formation with in-form Hernandez proving impossible to leave out. Fabio started at right-back with Antonio Valencia, Michael Carrick, Giggs and Ji-sung Park forming the midfield quartet.
In a breathless opening period, both sides carved out chances with Edwin van der Sar worked by Alexander Baumjohann and Edu while Neuer showed his class at the other end. Rooney drifted inside to force a diving stop out of the Schalke skipper, who then beat out a Park drive. Some fine work by Fabio and Valencia led to Hernandez stretching to test Neuer again. Hernandez was then in a one-on-one with the keeper in the 14th minute when Park's astute through ball found him just onside but the Mexican couldn't squeeze his finish under Germany's number one.
Hernandez remained the man likeliest to open the scoring as he rippled the side-netting with a left-footed effort and then made the wrong decision in trying to return a pass to Rooney rather than going for goal himself. Chicharito seemed to be finding space easily and, when he was beautifully picked out by Valencia, it was a surprise his snap-shot flashed across goal rather than on target from an angle.
But it was Giggs who almost broke the deadlock when getting his head to Nemanja Vidic's cross, only for the outstanding Neuer to scoop the ball away with his right hand.
Christoph Metzelder took a booking for the team with a cynical foul on Rooney to stop the England international releasing Hernandez again as the one-way traffic on the German goal continued. There was another major scare for Schalke when Hernandez nipped in to again force a fine stop out of Neuer and Park's goalbound rebound was blocked by Atsuto Uchida.
Moments later, Fabio fired over the top with his left foot from Park's header down as United tried to get the goal the Premier League leaders' dominance deserved. Instead, Neuer blocked crucially again to thwart Giggs in yet another one-on-one situation by standing tall to frustrate the Welshman with his seventh save of the half as the teams went in all-square at the break.
It took one minute and 13 seconds of the second half to test Neuer again as Carrick headed a Giggs free-kick goalwards before Giggs' dreadful right-footed finish ruined the calm dummy that sat two defenders on the deck.
Neuer was finally beaten with 51 minutes on the clock but, frustratingly, Hernandez was marginally offside when lashing home a superb finish. The Miners mustered an attempt of their own when Juan Manuel Jurado sliced a volley off target following Jefferson Farfan's lightning run down the right and Edu's powerful shot forced a save out of van der Sar.
But the Reds were merely biding their time before conjuring up a way of beating Neuer. Patrice Evra fed Rooney and the striker's brilliant disguised pass allowed Giggs to race through unchallenged to slip home an assured left-footed finish.
Scenting blood, United poured forward and, after Giggs volleyed a well-placed Valencia cross wide, it was 2-0 within a couple of minutes. Valencia touched the ball towards Hernandez and the summer signing helped it on intelligently to Rooney, who gleefully swept past the exposed Neuer.
Sir Alex took the opportunity to give Hernandez and Park a breather ahead of the weekend clash with Arsenal as Paul Scholes and Anderson came on with 17 minutes left.
Schalke tried in vain to reduce the deficit with Farfan sending a free-kick wide and substitute Sergio Escudero's excellent attempt forcing van der Sar into evasive action.
But the hosts, who almost fell further behind late on when Evra shot just wide after linking up with substitute Nani, were simply no match for the Reds on the night and require a Minor miracle in the second leg at Old Trafford next Wednesday.