Captain Jonathan Thomas saw red as Worcester's winless run continued with a 30-14 defeat at Northampton, who reclaimed top spot in the Aviva Premiership table.
Thomas was sent off for punching Northampton number eight Sam Dickinson, who was one of three men to be yellow-carded in a frantic encounter at Franklin's Gardens.
Wayne Barnes, refereeing a Saints game for the first time since the Premiership final last May, also sin-binned Leonardo Senatore and Sam Betty as the Warriors failed to keep their cool.
Northampton earned the win thanks to a penalty try and two efforts from GJ van Velze, who will join the Warriors next season, with Stephen Myler adding 15 points with the boot.
Worcester, who had been ahead early on, responded with a David Lemi try and nine points from full-back Chris Pennell.
But the cards were to cost them a shot at claiming their first win in 14 attempts this season.
The Warriors had started brightly and were first on the board as a penalty at the scrum handed Pennell the chance to land his side's first points from in front of the posts.
But the full-back was unable to nail a much tougher kick from near halfway and Northampton's first venture into Warriors territory was rewarded with a Myler penalty.
Northampton were soon in front as Myler made the most of Betty going over the top at a ruck to secure another three points.
And Northampton were 9-3 up soon after as Alex Waller dominated in the scrum, winning a penalty and Myler made it three from three from the tee.
Worcester's discipline was starting to be called into question and they were reduced to 14 men 10 minutes before the break as Senatore was sin-binned for obstruction.
The Warriors' resilient first-half showing was capped by a Pennell penalty on the stroke of half-time.
Northampton were in determined mood at the beginning of the second half and upped the power levels, forcing Barnes to award a penalty try from a huge driving maul.
Myler made it 16-6 with the conversion, but while Worcester were down they certainly were not out.
And Lemi mounted an immediate response, latching on to a neat Alex Grove grubber kick to score and breathe new life into his side's bid.
But indiscipline was to catch up with Worcester again soon after as Thomas saw red for punching Dickinson, who was yellow-carded for pulling back James Percival.
And the Warriors were down to 13 men when Betty was punished for pulling down a maul.
Van Velze was the man to profit from a line-out drive, with Myler making it 23-11 with the conversion.
Pennell again issued a retort from the tee to cut the gap to nine points but Van Velze grabbed his second of the afternoon and Myler added the extras to take Northampton up to 30 points.