The attacking Blancos trio were on fire at the Veltins Arena and clinically left die Knappen staring down a probable Champions League exit
The Blancos opened the scoring in Germany early on when Bale's ball was flicked through die Knappen's defence by Ronaldo for Benzema to pounce and bury in the back of the net, before the Welshman grabbed a goal of his own, weaving into the box then finishing in the bottom corner.
Ronaldo had plenty of chances to add his name to the scoresheet but struggled to find the net, but finally slammed one his shots home as the second half plodded along, with Benzema converting from a tight angle on a Madrid counterattack shortly afterwards.
Sergio Ramos carved open Schalke's decimated defence with 20 minutes still remaining and Bale duly delivered the visitors a fifth at the Veltins Arena, burying the ball neatly into the back of the net.
Ronaldo capitalised on lackadaisical Schalke defending by waltzing in a sixth for Madrid with a minute left on the clock, although Klaas-Jan Huntelaar bagged the goal of the night by volleying home an absolute beauty in stoppage-time for the hosts.
The comfortable victory sees Jens Keller's men facing almost-certain elimination from Europe at the last 16 stage and eases any pressure on Carlo Ancelotti's side - who hade only won one of their last 25 visits to Germany in Uefa competition - ahead of the return leg at the Santiago Bernabeu on March 18.
Keller had spoken in the build-up about the Germans' need to be "brave" against a side he ranks as arguably the second best in the world - behind Schalke's Bundesliga rivals Bayern Munich - but there was little his side could do about Madrid's opener.
Ronaldo's flicked pass was deflected into the area for Benzema and the Frenchman coolly slotted past Ralf Fahrmann to give the visitors a perfect start.
Schalke should have levelled a minute later, however. Draxler darted in behind the visitors' defence to direct Jefferson Farfan’s right-wing cross past Casillas, but the Spaniard launched himself across goal to palm it away, before Meyer blazed the rebound over.
Madrid made the most of that let-off and doubled their lead 21 minutes in, with Bale showing his class.
After cutting in from the right, the Welshman cleverly slalomed his way between Felipe Santana and Sead Kolasinac before squeezing a shot into the bottom-right corner, capping a wonderful solo run.
Ronaldo almost made it 3-0 just after the half-hour mark, but after jolting past Kolasinac and shooting from 20 yards, his low drive came back off Fahrmann’s right-hand post.
Ronaldo finally got a deserved goal in the 52nd minute and he netted in style as the Ballon d'Or winner dazzled Joel Matip with three stepovers before charging into the area and rifling in a left-footed effort.
A fourth arrived just five minutes later as Benzema doubled his tally for the match, passing into an empty net after playing a one-two with Ronaldo and bursting around Fahrmann, but things soon got even worse for the hosts.
With 21 minutes remaining, Bale raced on to an intricate throughball from Ramos and confidently caressed the ball past the goalkeeper with his left foot.
The visitors added a sixth for good measure as Ronaldo latched on to Benzema's pass, skipped past Fahrmann and passed home.
There was still time for Schalke to get a consolation as Huntelaar fired in a superb volleyed effort from the edge of the area, but Real had already long since killed off the tie.