A penalty awarded after a VAR review and converted by Harry Kane was enough to give Tottenham a narrow 1-0 lead after the first leg of their Carabao Cup semifinal against Chelsea at Wembley.
Video officials checked whether Kane had been onside when he went down under goalkeeper Kepa Arrizabalaga's 24th-minute challenge -- and after finding he was and reviewing the challenge, the 26th-minute penalty from which the striker scored the game's only goal was given.
Spurs' Son Heung-Min had been first to threaten when he tried to accelerate away from Andreas Christensen and went to ground under the defender's challenge, but his appeals were waved away.
Chelsea hit back as Ross Barkley's shot hit the side netting, and then Kane's bicycle kick from a Kieran Trippier cross was clutched by Kepa.
With less than 10 minutes gone and the game end-to-end, Willian picked out Callum Hudson-Odoi, who tested Paulo Gazzaniga, Willian's cross flicked over by Barkley soon afterwards.
Trippier, Son and Harry Winks linked as Spurs moved the ball around the Chelsea penalty area only for Christian Eriksen to overhit his cross, and Barkley ballooned over soon afterwards as the visitors looked to retaliate.
Eden Hazard's curler from 25 yards was comfortably fielded by Gazzaniga -- and moments later came the VAR intervention from which the first leg was settled as Kane kept his cool to fire into the corner, with Kepa shown a yellow card.
Winks joined the Chelsea keeper in the book for a foul on Hazard before N'Golo Kante had a deflected shot stopped and Willian's dangerous low cross was cleared by Toby Alderweireld.
Five minutes from the end of an entertaining first half, Kante's flick hit the outside of a post before Gazzaniga touched a Hudson-Odoi cross onto the inside of an upright after it deflected off Danny Rose, Alderweireld belting the rebound away to ensure Spurs led at the break.
Antonio Rudiger made a fine challenge to deny Dele Alli inside the area as Spurs began the second half on the front foot, but Chelsea soon hit back and Hazard forced a corner with a deep cross after a jinking run into the Tottenham box.
Kane was close to his second when, after fine build-up play involving Moussa Sissoko and Alli, his strike from distance was well saved by Kepa, and Kante was denied by Gazzaniga when he hit a drive moments later.
With Chelsea beginning to get on top and dominating possession, the excellent Hudson-Odoi fired in another cross that was dealt with by Trippier -- and the visitors could have levelled when Christensen, free at the far post, steered wide.
Davinson Sanchez was booked for fouling Hazard with Spurs struggling to get on the ball, and Chelsea's No. 10 gave Mauricio Pochettino further cause for concern with a run that brought his side another corner.
Visiting manager Maurzio Sarri introduced Pedro for Willian with a little under half an hour remaining and Chelsea looking to increase the pressure, but Spurs almost hit back when Son steered the ball towards Sissoko inside the area but just too far in front of him.
With 75 minutes gone, Chelsea appealed for handball when Hazard's attempted pass cannoned off Alderweireld, but play was waved on before Jorginho shot over and Sarri replaced Barkley with Mateo Kovacic.
Spurs made a change as the game headed for its final 10 minutes, Son replaced by Eric Lamela, and Chelsea brought on Olivier Giroud, Hudson-Odoi coming off.
Lamela went into the book for a hefty challenge on Hazard, and Alonso wasted a good position for Chelsea when he crossed into Gazzaniga's gloves with Giroud waiting in the middle.
Spurs brought on Oliver Skipp and Fernando Llorente for the final few minutes, Winks and Eriksen making way as Spurs held onto their lead ahead of the second leg at Stamford Bridge on Jan. 24.