Longstaff, dismissed for sliding challenge on Ruben Neves, will miss the club’s next three games through suspension.
Newcastle had deservedly led at St James's Park through a first-half goal from Jamaal Lascelles. However, Steve Bruce’s side, up against a team which had played away in Slovakia on Thursday night, lost control of the game after the break.
The result left United 17th in the Premier League.
Newcastle had struggled to turn their possession into chances. Miguel Almiron mishit an early opportunity at St James’s Park, where there were again thousands of empty seats.
Owner Mike Ashley, again, was not at the game, though Keith Bishop and Justin Barnes, his associates, were in the directors’ box.
Almiron’s second chance lifted the previously-subdued crowd. The midfielder shot into the side netting after a quick break forward.
The crowd responded to an improvement from Newcastle, and the breakthrough came in the 37th minute after Wolves only failed to deal with a ball into the box. Federico Fernandez, in for the injured Fabian Schar, took the ball on the right and delivered a superb cross for the oncoming Lascelles, who beat Rui Patricio with a close-range header. The strike was Lascelles’ first since January last year.
United ended the half on top, but Wolves fought back after the break. Newcastle just couldn’t keep the ball, and they retreated deeper and deeper into their half
There was an inevitability about the visitors’ equaliser, which was scored by Jonny from 10 yards after Martin Dubravka got a hand to a cross from Matt Doherty.
Wolves didn’t look tired, despite their Europa League exploits, and things got worse for Newcastle in the 84th minute when Longstaff was sent off for challenge on Neves. United held on to claim a point.
NEWCASTLE UNITED: Dubravka; Yedlin, Fernandez, Lascelles, Clark, Willems; Almiron, M Longstaff (Atsu, 90), S Longstaff, Saint-Maximin (Gayle, 90); Joelinton (Shelvey, 85). Subs not used: Darlow, Krafth, Dummett, Muto.
WOVERHAMPTON WANDERERS: Patricio, Doherty, Dendoncker, Coady, Saiss, Jonny (Vinagre, 84), Moutinho, Neves, Adama, Jiminez, Jota (Neto, 70). Subs not used: Ruddy, Vallejo, Cutrone, Kilman, Ashley-Seal.