West Brom manager Roberto Di Matteo felt the home crowd tried to influence referee Jonathan Moss in his side's stormy 3-1 win at nine-man Scunthorpe.
Scotland midfielder Graham Dorrans scored a goal in each half - either side of Rob Jones' first goal for the Iron - in an eventful Championship clash at Glanford Park.
Dorrans should have had a hat-trick but missed a penalty as Scunthorpe lost their discipline in the second half, with Andrew Wright and Grant McCann sent off.
Gianni Zuiverloon sealed the points with a third goal five minutes from time to ensure second-placed Albion maintained their two-point lead over Nottingham Forest.
Di Matteo said: "As far as the two penalties are concerned, I did not really get a good view of the first decision but the second looked a clear penalty to me.
"My players had to be careful to keep their discipline because the home crowd were trying to influence the decisions of the referee.
"Graham Dorrans is normally very good from the penalty spot and it was disappointing to see him miss his second effort."
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