Premier League leaders Arsenal held on to win at Leeds in a dramatic finish after the match had been delayed by about 40 minutes because of a power outage.
There was drama in stoppage time when referee Chris Kavanagh sent off Arsenal's Gabriel for kicking out at Leeds striker Patrick Bamford and awarded the hosts a penalty, but both decisions were overturned after Kavanagh reviewed the incident on the pitchside monitor.
Earlier, he halted the match after 23 seconds of play because of a power cut at Elland Road, which meant Kavanagh lost communication with the video assistant referee (VAR) officials, while goalline technology was down too.