Middlesbrough cruised past Preston, who had midfielder Alan Browne and manager Alex Neil sent off in a chaotic match at the Riverside in the Championship.
In a torrid first half for the visitors, Preston defender Jordan Storey sliced Yannick Bolasie's cross into his own net before skipper Browne was sent off for an off-the-ball clash with Sam Morsy on the halfway line.
North End manager Neil had a lengthy verbal exchange with referee Oliver Langford after the half-time whistle before being sent to the stands by the official.
Against 10 men, Middlesbrough repeatedly cut through the visitors' defence, with Marcus Tavernier doubling the lead in the 51st minute, but they were unable to make the victory even more convincing.