Premier League - Ten-man West Brom beat Villa
The hosts overcame Abdoulaye Meite turning the ball into the back of his own net to level just after the interval, only to have Scharner sent off just minutes later.
But Youssuf Mulumbu rescued three points for the home side when he picked the ball up on the penalty spot, turned and fired home six minutes from time.
As befits two mid-table teams, the final ball was often missing, despite bright and promising play from both players, and it took a moment of aberration and a red card to swing the match in Villa's favour.
And yet it was West Brom who came away with the three points as Mulumbu poached a goal with just four minutes to go, the Baggies moving up to 11th, albeit having played one match more than 12th-placed Newcastle.
Led by caretaker manager Gary McAllister in the ongoing absence of boss Gerrard Houllier, the visitors made a bright start to the match, pushing West Brom deep into their own territory.
Kyle Walker made a speculative attempt at a shot from the right wing but there had been little time for any momentum to develop before Meite suffered a complete aberration.
The Ivorian, under little pressure from any Villa forward, contrived to turn Stewart Downing's cross from the right into his own net despite having to twist his body into an awkward position to do so.
Scott Carson had little chance to make the save, no doubt expecting his centre back let the ball run through to safety, but instead seeing it fly past his left and into the back of the net.
Such was the unexpected nature of the goal that even Aston Villa seemed disbelieving, offering little in the way of celebration as a confused hush descended over the Hawthorns.
The incident clearly rattled West Brom and the visitors almost doubled their lead just minutes later when Carson failed to hold on to Stiliyan Petrov's shot from the edge of the box, only just getting the ball back under control before the fast-approaching Darren Bent could turn it back into the net.
The Baggies gradually played their way into the match, however, and Mulumbu had a fantastic opportunity to level the scores in the 20th minute, the Congolese finding himself in acres of space 30 yards out before unleashing a bullet that Brad Friedel did very well to palm away for a corner.
Bent had the only other real chance of the match turning on the penalty spot to lift the ball over Carson's shoulder, only to be flagged, rightly, offside.
And the second half looked like progressing in much the same manner, with both sides enjoyed multiple chances but failing time and again to find that final ball.
Odemwingie got things back on track for the hosts on the hour mark when he latched on to a loose ball after both Scharner and Simon Cox had scrappy shots blocked.
Almost immediately the momentum swung back in Villa's favour, Scharner being shown a second yellow card for wrestling Petrov to the ground.
Villa, meanwhile, consistently missed simple opportunities to take the lead with Young the worst offender, somehow heading wide from just six yards out.
But Mulumbu stepped up to the plate, just seconds after being booked, picking up the ball just inside the are before dinking his shot around the flailing Friedel.
And, despite an excruciating seven minutes of added time, West Brom held on for the win as a deflated Villa failed to get another shot on target.