FC Barcelona's Denis Saurez (C) fights for the ball with Hercules players during the King's Cup round of 32 match between Hercules and FC Barcelona at Jose Rico Perez stadium in Alicante, Valencian Community, Spain, November 30, 2016. [Photo/IC]

MADRID - FC Barcelona were in danger of falling victim to one of the few shocks in the first leg ties of the King's Cup knockout tournament when they were held to a 1-1 draw against second division B side, Hercules.

Barca went into the game with question marks surrounding their form, and the first half display in Alicante did nothing to allay concerns, as a side made up of fringe players and B-teamers went in 0-0 at the break against a rival which plays two levels below them.

An upset looked on the cards when David Mainz took advantage of some shoddy defending to chest Hercules ahead in the 52nd minute before youngster Carlos Alena equalized with a powerful shot just six minutes earlier.

The 1-1 dram makes Barca favorites to qualify in the return leg, but is far from being a confidence booster ahead of Saturday's Classico at home to Real Madrid.

The only surprise of the day came when second division side Cordoba beat Malaga 2-0 with second half goals from Rodri and Borja Dominguez.

Real Madrid meanwhile played the return leg of their tie against Cultural Leon, although their 7-1 win from the first leg meant there was no doubt about which side was going into the next round.

It was 8-1 on aggregate after just 23 seconds when Mariano scored the fastest goal in Madrid's Cup history. He and James Rodriguez added further goals before the break as Real Madrid went on to qualify 13-2 on aggregate with Zindine Zidane's son Enzo scoring his side's fourth of the night and Mariano completing his hat-trick in the second half.

Elsewhere they were no surprises: Joaquin Correa scored a first half hat-trick as Sevilla cruised to a 5-1 first leg win away to Formentera to all but qualify for the last 16 of the tournament.

Villarreal also had their game away to Toledo quickly under control as an own goal and a smart finish from Cedric Bakambu gave them a 2-0 lead as early as the 20th minute.

Toledo fought bravely in the second half and it was cruel on the third tier side when Samu Castellejo netted Villarreal's third on the break with less than 10 minutes remaining.

Atletico Madrid also strolled through their first leg tie winning 6-0 away to Guijuelo thanks to a very questionable Saul Niguez penalty and a volley from Sime Vrsaljko in the first half.

They then ran riot after the break with two strikes from Yannick Carrasco, one from Angel Correa and a debut goal from Roberto Nunez to make the return leg a mere formality.

Jon Toral's second half goal was enough to give Granada a 1-0 win at home to Osasuna in what was their first win of the campaign in all competitions, while Sergi Gomez's goal took Celta to a 1-0 in away to second division UCAM Murcia.