The substitute levelled in stoppage-time just as Cameron Archer’s 87th-minute strike looked to have given the Blades a stunning smash and grab win.

Villa needed victory to go top but now sits second, behind Arsenal on goal difference.

The Blades, meanwhile, still climbed off the bottom of the table after coming so close to a brilliant, resilient, victory.

Leon Bailey had a goal disallowed and the hosts had three penalty claims rejected by VAR as they failed to make their dominance count.

It was supposed to be Villa’s ascension to the top of the Premier League, somewhere it had not been, outside the opening weeks of the season, since December 1998.

The contrast could not have been more different from three-and-a-half years ago when Villa drew 0-0 with the Blades and sat second bottom after the first game of the Premier League’s "Project Restart" after the COVID-19 outbreak.

Back then, in an empty stadium, Villa was fortunate to avoid defeat after Orjan Nyland fumbled Oliver Norwood’s free-kick over the line, only for referee Michael Oliver’s watch to fail to signal a goal.

It was a pivotal point in Villa’s fight for survival which, ultimately, gave it the platform to build.

Now, the fact it missed its chance to go above Arsenal, will not diminish its progress, although boss Unai Emery was noticeably angry at full-time after being frustrated by the gutsy visitors.

Blades boss Chris Wilder packed a five-man defence to contain the hosts and United lived dangerously early when Ollie Watkins was shoved by Vini Souza as he lurked for Lucas Digne’s cross.

VAR rejected Villa’s penalty appeals and then disappointed the hosts again when George Baldock blocked Watkins’s header from the resulting corner.

Inevitably, Villa was the aggressor with Wes Foderingham’s smart stop denying Moussa Diaby and Ezri Konsa heading over but there was no early procession.

With 15 straight home wins, the expectation was on Villa to roll the bottom side over but patience was still needed and Watkins hooked over from a Clement Lenglet knockdown.

It was one-way traffic, just without the goal, and the compact Blades would have been very content at the break.

Yet Wilder would have been fuming after 58 minutes when his side looked to have gifted Villa the opener until VAR intervened.

Baldock was sloppy as he tried to play the ball out as United cleared a corner and was robbed by Watkins, who swapped passed with Jacob Ramsey.

The England striker then crossed for Bailey to sweep in but play was eventually pulled back as Ramsey had fouled Foderingham at the corner.

Another VAR reprieve for the visitors came 15 minutes later when Baldock survived a handball review as Villa Park became increasingly anxious.

It emboldened the Blades and Norwood tested Emiliano Martinez from distance, their first shot, after 78 minutes before Konsa almost sliced Max Lowe’s cross into his own net.

Archer’s shot was blocked and Norwood drove over before United stunned Villa Park with three minutes left.

Vini Souza’s free-kick found Gustavo Hamer running behind and a brilliant piece of skill from the midfielder saw him leave John McGinn floundering.

The substitute then had the presence of mind to cut the ball back for Archer to convert from six yards.

Foderingham saved Alex Moreno’s header but Villa found a leveller deep into stoppage-time when Zaniolo headed in Douglas Luiz’s cross.