It was a straightforward evening for Zinedine Zidane's side, but one with plenty of talking points. Striker Mariano bagged himself a hat-trick, Enzo Zidane scored 18 minutes into his debut and Norwegian teenage sensation Martin Odegaard was also given his first start for the club.
Taking a 7-1 lead from the first leg against the third division side, a much changed Real Madrid side showed no mercy to their lower league opponents and starting with a bang.
It took the La Liga leaders just over 30 seconds to go into the lead as Mariano finished from a Marco Asensio cross.
Madrid doubled their lead midway through the first half through James Rodriguez. The Colombian made a run into the box and headed home from Dani Carvajal's cross.
The home had their third just before half-time, with Mariano getting his second of the evening. However, there was still enough time for Leonesa to get a consolation goal and what a goal it was.The ball broke to Yeray after Carvajal made a challenge and smashed an effort from just outside the area into the top corner to give the minnows something to celebrate.
Zinedine Zidane decided to bring off Isco at half-time, possibly with one eye on 'El Clasico' at the weekend, and brought on his son Enzo who didn't disappoint. Just 18 minutes into his Madrid debut, with his first shot for the club, the midfielder fired into the bottom corner from the centre of the box.
Less than three minutes from time, Mariano had his hat-trick when he headed home from a Tejero cross and Madrid managed to score a sixth goal when Cultural Leonesa's Cesar Morgado put the ball into his own net.