Crowd trouble marred Wolves' 2-0 FA Cup victory over local rivals West Brom as play was halted due to violence in stands on Sunday. Referee Thomas Bramall halted play late in the second half at the Hawthorns as fans spilt on to the pitch after fighting had broken out at one end of the stadium. Play resumed after a delay of 38 minutes and the final 12 minutes of the match concluded with no further incidents. Wolves were leading 2-0 when projectiles were hurled on to one end of the pitch in the 82nd minute, sparking a brawl. Fans spilled on to the pitch, prompting players to leave the field. When players returned and the match resumed, with the clock reset to 77 minutes 10 seconds, the time that Matheus Cunha had scored Wolves' second goal. Pedro Neto had scored in the first half for Wolverhampton who booked their berth in the fifth round with the victory. "Of course we are disappointed with any type of incident like that," West Brom manager Carlos Corberan told ITV. "Unfortunately, the game was interrupted by this incident and now, we are unable to talk about the atmosphere our fans created, we can't talk about this aspect. We are totally disappointed by this. "Everything before the incident was unbelievable, between both clubs it was very special and incidents like that we need to avoid." Wolves manager Gary O'Neil called the disturbance "really disappointing". "Up until that point it was a good tie with good atmosphere," O'Neil told ITV. "How people behave at football is really important and we need to look at that, make sure everyone is safe. When we came back out the atmosphere had gone, it was really sad to see." The ugly scenes came in the first meeting between the bitter rivals with fans allowed in 12 years. The Football Association launched an investigation into the crowd trouble. West Midlands Police said two people were arrested after the disturbance and another was arrested prior to the match for possession of a weapon, while a man was taken to hospital with head injuries. "The disorder that occurred at the Black Country derby between West Bromwich Albion and Wolverhampton Wanderers is completely unacceptable," an FA statement said. "Safety and security are of the utmost importance, and the behaviour of those involved is dangerous and inexcusable. "We will be investigating these serious incidents alongside the clubs and the relevant authorities, and the appropriate action will be taken." Meanwhile, Liverpool cruised into the fifth round of the FA Cup with a 5-2 rout of Championship side Norwich City to kick off manager Jurgen Klopp's long goodbye at Anfield. Liverpool's beloved manager announced on Friday that he would leave the Merseyside team at the end of this season, his ninth at the helm. The eight-times FA Cup winners had goals from Curtis Jones, Darwin Nunez, Dioga Jota, Virgil van Dijk and Ryan Gravenberch. Liverpool will next play either Watford FC or Southampton after that fourth-round game earlier ended in a 1-1 draw thanks to a last-gasp goal by Southampton's Stuart Armstrong to force a replay.