Chelsea were awarded a penalty in the closing stages of the first half against Tottenham after VAR overturned a bizarre decision from referee Anthony Taylor.
With Chelsea leading 1-0 courtesy of a goal from Willian, Tottenham goalkeeper Paulo Gazzaniga raced forwards and ended up clattering into Chelsea defender Marcos Alonso.
Bizarrely, Taylor initially punished Alonso for the incident, with Tottenham being given a free-kick, but VAR was then consulted.
Eventually the decision was overturned, with Chelsea being given a penalty and Gazzaniga receiving a yellow card.
Willian stepped up to take the penalty and ended up getting the better of Gazzaniga to make it 2-0.
Sky Sports commentator Gary Neville described Gazzaniga's challenge as 'an assault'.
It was a heated first half at Tottenham Hotspur Stadium, with other flashpoints occurring.
For instance, Tottenham's Moussa Sissoko fouled Chelsea goalkeeper Kepa Arrizabalaga but wasn't booked.
In addition, Chelsea midfielder Mateo Kovacic was involved in a contretemps with opponent Dele Alli.