Tottenham Hotspur defeated Chelsea 5-4 in a penalty shootout to progress in the League Cup in their fourth round clash on Tuesday, after the game finished 1-1 in normal time. Chelsea's Mason Mount struck the post to miss the decisive fifth penalty after every other spot kick had been scored. Germany forward Timo Werner scored his first goal for the club to fire them into a 19th-minute lead, turning and lashing the ball into the net from the edge of the area after receiving a cut-back from Cesar Azpilicueta. Chelsea's new goalkeeper Edouard Mendy enjoyed a solid display in his first game since switching from French side Rennes, making a good save to keep out a shot from Spurs' debutant Spanish left-back Sergio Reguilon in the second half. But Mendy was beaten in the 83rd minute when Reguilon turned in the box and crossed for Erik Lamela, who prodded home from close range to force the shootout in which Tottenham prevailed. An urgent trip to the bathroom by Spurs' defender Eric Dier led to the surreal sight of the defender running off the pitch during the match – with manager Jose Mourinho chasing down the tunnel after him. Spurs were trailing 1-0 with 15 minutes to go when Dier raced off the pitch and darted towards the dressing room, quickly followed by Mourinho, whose side were briefly down to 10 men in their fourth round home clash. Mourinho soon returned to his dugout and Dier swiftly made it back onto the pitch, helping Tottenham find an equaliser. "Jose wasn't happy but there was nothing I could do about it, nature was calling," said Dier, who scored during the shootout. "I heard there was a chance [for Chelsea] while I was off the pitch but thankfully they didn't score."