This Van Persie red card vs Barcelona turned Arsenal’s second leg Champions League tie with Barcelona on its head. The Van Persie red card was given by Swiss referee Massimo Busacca at a crucial juncture in the game ( the game was tied at 1-1). Barcelona eventually won the tie 3-1, and progressed 4-3 on aggregate.
The Van Persie red against Barcelona was given for accumulating two yellows, although the second yellow looks a tad controversial ( as you can see from the video below.)
Video- Van Persie red card vs Barcelona- 8/3/11
( Credits of this Van Persie red card video with uploaders)