The Magpies fell behind in controversial fashion at Villa Park as Tammy Abraham swept the ball home from Douglas Luiz's free-kick, despite initially straying into an offside position, but the goal stood following no VAR in operation for the fourth round tie.
Villa were reduced to ten men on the stroke of half-time following Marco Bizot's straight red card following the goalkeeper's wild foul on Jacob Murphy and Newcastle made their advantage count in the second half.
Tonali netted an impressive second-half brace, his first goals of the 2025/26 season, before Nick Woltemade, celebrating his 24th birthday, netted his first goal since December in the closing stages as Eddie Howe's side recorded back-to-back away wins for the first time since April.
The Magpies, backed by over 6,500 away supporters this evening, trailed in the 14th minute as Abraham latched onto Luiz's well-improvised free-kick inside the box before sweeping the ball beyond United goalkeeper Aaron Ramsdale.
The striker was situated in an offside position following Luiz's pass but, with no VAR in place for the cup tie, the goal stood.
Harvey Barnes, who scored a brace in Newcastle's FA Cup third round win against AFC Bournemouth, went close to drawing the visitors level as the left winger completed a neat one-two with William Osula before crashing an effort into the side-netting.
Luiz almost turned from provider to goalscorer as the Brazilian midfielder let fly from distance but the ball, to the relief of the Magpies, flew narrowly over the crossbar.
Villa were fortunate not to receive a red card prior to Bizot's dismissal as Lucas Digne committed a late foul on Jacob Murphy, with referee Chris Kavanagh only brandishing a yellow card to the Villans captain.
Bizot, however, was sent off on the stroke of half-time as the Dutch goalkeeper raced off his line before taking out Jacob Murphy with a wild swipe towards the half-way line.
Newcastle were appealing for a penalty as Kieran Trippier's cross looked to strike Digne's arm but despite the Frenchman being situated inside the box, Kavanagh awarded a free-kick to the astonishment of the visitors.
Justice was served, however, as Tonali drew United level from the resulting set-piece as the ball fell to the Italian on the edge of the box, who drilled a powerful deflected effort beyond Villa substitute Emiliano Martínez.
Anthony Gordon, introduced from the bench after Tonali's leveller, went narrowly close to firing Newcastle ahead as the ball landed kindly into the England international's path but his snapshot deflected wide of the left-hand corner.
In the 77th minute, Tonali netted his and Newcastle's second goal of the night in stunning fashion. After Amadou Onana headed the ball clear from the box, Dan Burn teed up Tonali on the edge of the box before the midfielder drove a terrific low effort into the bottom left-hand corner.
With the full-time whistle nearing, Woltemade marked his 24th birthday with his tenth goal of the season in all competitions for the Magpies.
After Joe Willock pounced upon Lamare Bogarde's wayward pass inside the box, the ball kindly worked its way into the German forward's path, who lifted the ball into the roof of the net to confirm Newcastle's passage into the competition's fifth round stage for a third successive campaign.
Newcastle United: Aaron Ramsdale, Kieran Trippier (c) (Alex Murphy 90), Lewis Hall, Sandro Tonali, Harvey Barnes, Malick Thiaw, William Osula (Anthony Gordon 64), Jacob Murphy (Anthony Elanga 64), Nick Woltemade, Dan Burn, Jacob Ramsey (Joe Willock 80).
Subs not used: Nick Pope, John Ruddy, Leo Shahar, Sean Neave, Seung-soo Park.
