The scuffle - fifteen minutes from the end - began when Barton took exception to Gervinho's dive. The ensuing row, which involved multiple players from both sides, saw Gervinho sent off after slapping Barton in the face. Barton received a caution.
Earlier, Alex Song had stamped on Barton's ankle, an incident that went unpunished by referee Peter Walton.
Despite facing ten men, the Magpies were still unable to break through in the closing stages and had to settle for a goalless draw at St James' Park.
Arsenal next face Liverpool at the Emirates on Saturday, while Newcastle travel to local rivals Sunderland.