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West Brom have pledged to investigate the pockets of crowd trouble that occurred during Chelsea's 1-0 victory at The Hawthorns on Friday and punish any supporters found to have sold their tickets to travelling Blues fans.
West Midlands Police have confirmed they made nine arrests -- seven men for pitch incursion, one for a public order offence and one for criminal damage -- following the win that saw Chelsea crowned Premier League champions for the second time in three seasons.