Middlesbrough claimed the bragging rights in the Wear-Tees derby with their biggest ever victory away to 10-man Sunderland.
Second-half goals from Leeds United loanee Sam Greenwood, Matt Crooks, Isaiah Jones and Marcus Forss made it four successive wins for Boro as they continue their recovery from a poor start to the season.
The turning point came in first-half injury time when Black Cats midfielder Dan Neil was sent off for a second yellow card.
The home team could not cope without him as they slipped to a fourth loss of the season, although they still remain in the top six.
These two had been losing Championship play-off semi-finalists last year, and have been starting to find form after slow starts to this campaign.
Roared on by another large Stadium of Light crowd - 43,584 - Patrick Roberts was close to putting Sunderland in front after a thrilling run, only for the outstretched boot of Boro goalkeeper Seny Dieng to keep his effort out.
But Boro showed ambitions of their own as Greenwood's effort was parried by Anthony Patterson and it needed desperate defending from Dan Ballard to prevent Josh Coburn from turning in the rebound.
However, the complexion of the game changed when Neil received a second yellow for dissent to referee Jarred Gillett, having earlier been booked for a foul on Coburn.
With tempers still boiling, Ballard reacted angrily to an aerial challenge from Coburn and the half-time whistle sounded with players pushing and shoving.
Boro boss Michael Carrick had to come on to the pitch to keep his players out of trouble with the end result being bookings for both Ballard and Coburn.
Matt Crooks grabbed his second of the season as Middlesbrough scored four second-half goals at the Stadium of Light
With an extra man after the break, the Teessiders took control and should have gone in front only for Patterson to make a wonderful save to deny Crooks at close range.
But a goal was coming and two in three minutes effectively sealed the game just before the hour.
First, Greenwood - a Sunderland boy and former academy player with them - flashed in his first Boro goal with a fine first-time finish before Isaiah Jones put one on a plate for Crooks to double the lead.
Jones slotted in a third to cap a fine individual display before substitute Forss grabbed a late fourth as Sunderland's afternoon got progressively worse.
Yet Boro continue to pick up momentum. After beginning with one point from a possible 18, they have taken 13 out of the last 15 as they begin to climb the table with aspirations of repeating last season's fourth place.