Manager Chris Ramsey was delighted QPR after gave themselves hope in their Premier League survival fight with this spectacular win.
Former England striker Bobby Zamora scored a fabulous lob as Rangers bagged just their second away win of the season.
Eduardo Vargas and Charlie Austin also scored first-half goals to give the visitors a 3-0 half-time lead before Joey Barton added a fourth in stoppage-time.
It ended Rangers' five-match losing run and they are a point from safety before today's games, and Ramsey feels it will give his side belief ahead of their crunch clash at Aston Villa on Tuesday.
"It's going to be a big boost - when you're getting beaten every week and performing well sometimes it's hard to see a way out," he said. "The players are keeping faith. We knew it was going to be very difficult to get any sort of result here but goals always lift any team's confidence.
"We've been close to that, it wasn't our best performance, it was a good performance, but we performed similar to that against Everton (a 2-1 defeat). We just haven't taken the chances in the same way."
Victor Anichebe pulled a goal back for Albion after the break but the Baggies never recovered from a first-half no show. Youssouf Mulumbu was also sent off six minutes from time after a challenge with Barton.
West Brom are eight points above third-bottom Rangers and manager Tony Pulis hinted that he thought his side were already thinking about the summer. "Getting to 33 points, people listen to social media and the press, but we haven't got over the line by a mile yet," he warned.
Sunday Indo Sport