Diego Simeone's 400th match in charge of Atletico Madrid ended with an ultimately comfortable 4-0 victory over Sant Andreu that sent them into the last 16 of the Copa del Rey.

Atletico's most decorated coach watched the from the stands at the Wanda Metropolitano due to a three-game Copa del Rey ban carried over from last season and his team had to weather a woeful first half before sealing the second-leg win and a 5-0 aggregate triumph.

Simeone made seven changes from the side that drew 1-1 with Girona at the weekend and they were fortunate not to go behind once again when Elhadji Bandeh hit the post for the fourth-tier visitors in the 33rd minute.

The introduction of Thomas Lemar for the second half proved key and his opener kick-started an eight-minute spell that included goals for Nikola Kalinic and Angel Correa, with Vitolo getting in on the act late on.

Sant Andreu had a chance to take a surprise lead after Santiago Arias sold Antonio Adan short in the 21st minute, but the goalkeeper recovered to deflect Josue Rodriguez's attempt over.

Bandeh struck the upright with a looping header and only a brilliant stop from Adan three minutes before half-time kept another effort from the striker out.

Lemar took less than three minutes to ease Atletico's concerns after replacing Toni Moya at the break by firing a powerful 20-yard drive in off the post.

The hosts doubled their lead five minutes later when Kalinic nodded Arias' right-wing cross beyond Jose Segovia.

Correa made it three in the 55th minute with a brilliant turn on the right side of the box and an exquisite finish inside the far post with the outside of his boot.

Sant Andreu were floored and the final blow came nine minutes from time, when Vitolo tapped home a cross from Saul Niguez.

What does it mean? Simeone forced to use key resources

This should have been a simple tie for Atletico's second string to see out convincingly, but their woeful first half forced the hosts into changes. Rather than being able to grant the likes of Lemar and Rodrigo a rest during a congested part of the calendar, they had to be used earlier than expected to avoid an upset.

Lemar changes the game

Kalinic spurned a pair of great opportunities and Bandeh threatened to punish them in the opening period. Any anxiety building within the Wanda Metropolitano dissipated when Lemar fired home the opener early in the second half. The World Cup winner finished the game with an assist for Correa and won the ball back to start the move from which Vitolo scored.

Gelson wastes his chance

His goal was the difference between the two sides in the first leg, but Gelson Martins was unable to make the most of just his third start of the season up front. The Portugal forward did not register a single shot or create a chance and the fact Kalinic, Correa and Vitolo all got on the scoresheet will likely hinder his hopes of an increase in game time.

What's next?

Atletico host Deportivo Alaves on Saturday and a win would, at least temporarily, send them joint-top of LaLiga. Sant Andreu will aim to return to winning ways against Europa.