Ireland international Shane Long put Albion in front after three minutes, controlling Chris Brunt's long ball superbly as it dropped over his shoulder before turning to fire past keeper Brad Guzan.
- How the teams stand in the EPL
Eight minutes later Long seized on a misplaced midfield pass from Villa's Leandro Bacuna to charge through the defence and chip the ball home for his second goal.
Stephane Sessegnon then missed from four metres for West Brom before Villa turned round a different side after the break.
Karim El Ahmadi reduced the deficit from close range and Ashley Westwood produced a fierce long-range drive - his first goal for Villa - to level in the 76th minute.
Both teams have 15 points from 12 games, Albion in 11th place and Villa in 12th.
Leaders Arsenal are four points clear on 28.
Image: Shane Long of West Bromwich Albion celebrates as he scores the team's first goal in the Barclays Premier League match against Aston Villa at The Hawthorns.
Photograph: Michael Regan/Getty Images
EPL PHOTOS: Chelsea win controversial tie, Suarez shines for Reds
Late penalty saves Mourinho's Chelsea home record
Euro soccer roundup: United down Arsenal; Bayern set Bundesliga record
EPL: What you must not miss this weekend
EPL PHOTOS: Slick Arsenal win to stay top; United, City lose