The Russian netted his fifth league goal of the season to complete Reading's astonishing comeback against the Baggies.
Brian McDermott's men had trailed 2-0 heading into the final 10 minutes at the Madejski Stadium, but goals from Jimmy Kebe and Adam Le Fondre brought the home side level before Pogrebnyak sealed the points in injury time.
Speaking to Rossiyskaya Gazeta, the 29-year-old said "This was a very important win. Everybody in the dressing room was shining with happiness."
The win brought the Royals within three points of safety and Pogrebnyak believes the team are finding form at a crucial point in the season.
He said "We will keep on fighting. This was a very important win and it's great that we have started to collect points."