The double-kick penalty that lost a shootout

Julian Alvarez slipped as he took Atletico Madrids second penalty

Real Madrid have Atleticos number in shootouts, having triumphed against them on every occasion the derby has gone to penalties.

But Wednesdays defeat in the last 16 of the Champions League will be particularly frustrating for Diego Simeones side.

Atleti midfielder Conor Gallaghers strike after 27 seconds had levelled the tie 2-2 on aggregate, but neither side could then find the decisive goal in normal or extra time, leaving penalties to decide the outcome between the rivals for a sixth time in knockout games.

There, Real Madrid won 4-2 in dramatic and controversial fashion. Defender Antonio Rudiger squeezed home the decisive penalty in the corner past Jan Oblak, but the hosts were left to rue Julian Alvarezs earlier disallowed effort in somewhat bizarre circumstances.

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Alvarez spot-kick ruled out for double touch

After the first three penalties had been successfully converted, ex-Manchester City forward Alvarez stepped up with the chance to make it 2-2.

The Argentina international slipped as he took his shot, but still managed to beat Thibaut Courtois.

Atletico fans were celebrating, but seconds before Fede Valverde fired home Reals next penalty, Polish referee Szymon Marciniak indicated Alvarezs spot-kick had been ruled out as the video assistant referee (VAR) got involved.

A review of the incident showed the forward touched the ball twice in one movement as he slipped while shooting.

"Thats bad luck, but its the rules," said Real keeper Courtois of the Alvarez incident.

The scoreboard in the ground displayed 2-2 after Alvarezs effort, no doubt leading to confusion in the stands, but at that stage Real actually led 3-1.

Although Atletico goalkeeper Oblak saved Lucas Vazquezs spot-kick to briefly give Atletico hope, Marcos Llorente hit the bar for the hosts and German Rudiger sent Real through in a tense finale.

Article 14.1 of the IFAB (International Football Association Board) laws of the game concerns penalties.

The rules state: "The kicker must not play the ball again until it has touched another player."

That is the same law that stops people scoring a rebound if their own penalty hits the post.

If the same happened from a penalty during regular play, an indirect free-kick would be awarded to the opposition.