The beIN Sports pundit backs Spurs to win - even without Dele Alli in the side.
Spurs go into the clash at knowing that a victory may preserve their slim hopes of a first title since 1961, but only if leaders Leicester City fail to beat Manchester United at Old Trafford this afternoon.
Mauricio Pochettino's side are 22 points clear of their West London neighbours, but another three are anything but a foregone conclusion as the Blues, under Guus Hiddink, looked impressive by beating Bournemouth 4-1 last time out.
Being London rivals, Chelsea might also want to kill the Lilywhites' title hopes once and for all - if Leicester don't beat United - but Gray backs the North Londoners.
Pochettino must make do without the services of star midfielder Dele Alli, who serves the first of a three-match ban, but even so Gray believes the Argentine has enough tactical nous to mastermind the three points.
"Spurs are missing Alli for the rest of the season and the dressing room will be down after the West Brom result. They are a young side but Pochettino has shown before that he’s a shrewd tactician in the face of adversity," he wrote on Paddy Power.com.
"Chelsea have been so impressive under Hiddink but have nothing to play for. The fans are key here. They love beating Spurs and if they do it on Monday night then they end the title race. They won’t have to beat or lose to Leicester to end it.
"This is Spurs’ last chance. But that’s the thing. They still have a chance. They’ve got to keep the pressure on Leicester. If the Foxes drop points, Spurs have to be ready. I’m backing them to win on Monday."