Guido Burgstaller and Mark Uth scored in either half as Schalke eased past Galatasaray 2-0 and tightened their grip on second place in Champions League Group D.
Burgstaller's opener – his first goal in the competition – after just four minutes was gift-wrapped by Galatasaray goalkeeper Fernando Muslera, who made a mess of collecting a throughball.
Domenico Tedesco's side should have put the game beyond the visitors' reach before half-time, but were denied by a combination of the woodwork, Muslera and some wayward finishing.
Uth settled any nerves with a cool finish 12 minutes into the second period to help Schalke open up a four-point gap over their third-placed opponents.
Schalke got off to a stunning start courtesy of some slapstick goalkeeping from Muslera, who – upon realising he was in danger of carrying the ball out of the area – released it into the path of Burgstaller, who whipped into an empty net from an acute angle.
That lead should have been doubled after 21 minutes, but Amine Harit inexplicably blazed over from 10 yards, while Muslera went some way to redeeming himself with a sharp block to deny Alessandro Schopf six minutes later.
Garry Rodrigues lashed a half-volley wide after breaking the offside trap in what was Galatasaray's best chance of the first half before Sebastian Rudy steered a 20-yard effort against the post and Muslera repelled Burgstaller's instinctive strike shortly before the interval.
Burgstaller turned provider for Schalke's second after 57 minutes, picking out an unmarked Uth with a low cross, which the former Hoffenheim man whipped past Muslera from 12 yards.
Fatih Terim's side rarely looked like setting up a grandstand finish as Schalke comfortably kept them at bay to put one foot in the last 16.
What does it mean? Schalke within touching distance
Schalke travel to Portugal in three weeks to face Porto knowing that a win will book them a last-16 spot. Galatasaray, meanwhile, know that third place and a berth in the Europa League beckons barring a series of dramatic results in the group's final two matchdays.
Burgstaller makes light of poor form
The Austrian striker has endured a torrid season – scoring just once in 15 appearances – but showed superb composure to curl home early on and set Schalke on their way to a fine victory.
Muslera's moment to forget
The Galatasaray goalkeeper let Antoine Griezmann's speculative effort slip through his grasp in Uruguay's World Cup quarter-final defeat defeat to France and he experienced another nightmare moment on Tuesday. There was no sympathy from Burgstaller, who mercilessly punished the 32-year-old with a clinical finish.
What's next?
Schalke return to Bundesliga action on Sunday with a visit to Eintracht Frankfurt, while Galatasaray travel to Kayserispor a day earlier in the Super Lig.
