Juve had their gap at the top cut to one point when they lost to Napoli last weekend and they were heading for another shock defeat after Mauro Icardi's 27th goal of the campaign and an Andrea Barzagli own goal put Inter within touching distance of a fine win. "We just have to let it go, our main goal is to play".
Douglas Costa fired in the opener for Juventus after 13 minutes following a cross from Juan Cuadrado.
Juventus thought it had scored a second just before half-time but the video assistant referee (VAR) showed Blaise Matuidi was offside when he found the net.
Juve were facing a dramatic defeat until Cuadrado's shot from an impossible angle deflected in off Skriniar with three minutes left.
In a weird finish, Allegri was sent to the stands for coming onto the pitch to celebrate.
Earlier, Roma hardly noticed having a man dismissed as they beat visiting Chievo 4-1 with a brace from Edin Dzeko helping them strengthen their hold on third place.
Eusebio Di Francesco's side is three points ahead of Lazio which plays Torino Sunday with Inter staying a further point back in fifth.
"Nobody handed us those results at the start of the season". The Tuscan club are clearly concerned about ramifications if away supporters end up mixing in with home fans, and although sales will not be allowed to Campania residents, there is clearly a potential for trouble in this high-stakes match.
Inter have a chance to derail Juve's chase for a seventh successive title when the two sides meet at San Siro on Saturday and boost their own hopes of qualifying for the Champions League after a six-season absence.
"I'm interested in what the three points mean for us, not denying three points from Juventus", he said. "And how must we be after seven years without winning anything?"