He was unfortunate with two swiftly-taken opportunities early on. Vassell was lurking near the far post when Turkish defender Ozalan Alpay headed a poor clearance by the Newcastle defence to his feet. He struck the sweetest of shots only for the ball to rebound off the upright. But he was able to regain his composure and fire in another volley which was headed off the line by centre back Aaron Hughes.
It was the signal for a concerted Villa assault that had a weakened Newcastle calling on all their resilience - and a superb performance by Harper - to keep the home side at bay.
It was easy to understand why manager Bobby Robson prefers Harper to Irishman Shay Given as the goalkeeper put up a seem-ingly impenetrable barrier against the bright and penetrative Villa attack.
Harper made a succession of first-half stops from Dublin, Lee Hendrie, Vassell and Steve Stone as the three-man central defence in front of him were pulled apart by the sheer enthusiasm of Villa's onslaughts.
But his save from Stone in the 35th minute was the most impressive of all. Alan Wright crossed in a deep ball from the left for Stone to take in full flight but his well- struck shot was deflected by Harper's outstretched arm.
Newcastle were pinned in their own half for much of the match and their only attacking effort of any note in the first half was a weakly- directed header by defender Alain Goma from a left-wing free kick from Stephen Glass.
While Newcastle were seriously hampered by the absence of Alan Shearer and the suspended Keiron Dyer and Nolberto Solano, Villa were nearer to their optimum strength with the return of midfielders George Boateng and Hendrie after their spells in soccer's sin-bin.
It was quite refreshing for Villa fans to see such a committed and adventurous performance from their side after successive home defeats in the League by Manchester United and Liverpool.
Perhaps it was the signing of Colombian Juan Pablo Angel that generated such a show of commitment from the likes of Vassell and, to a degree, Dublin. Whatever, it worked. Villa might have scored again just before the interval when a tremendous through ball by Boateng gave Merson a shooting chance from just outside the area but the veteran midfielder shot high into the terraces.
There was a potential hiccup for Villa when they lost their skipper and central defender Gareth Southgate through injury but Gregory was able to bring another England international Gareth Barry off the bench as his replacement.
Villa goalkeeper David James had to have his wits about him as his defence were caught out by a through ball which gave Kevin Gallacher an equalising opportunity in the 63rd minute. But before the striker had an opportunity to tee-up a shot, England keeper James had deftly taken the ball off his boot.
Vassell, who had run himself into the ground, was substituted in the 77th minute by another youngster Richard Walker after a job well done.
ASTON VILLA (3-5-2): James; Alpay, Southgate (Barry, 44min), Staunton; Stone, Merson, Boateng, Hendrie, Wright; Dublin, Vassell (Walker 77).
