The chastening loss completed a difficult week for United, after the club announced Thursday that women’s player Maddy Cusack died at the age of 27. The Blades paid tribute to Cusack with a moment of silence before the game.
Fans also stood up for a minute’s applause in the eighth minute for Cusack, who wore the No. 8 shirt.
It was Newcastle’s biggest away league win ever and equaled an 8-0 victory over Sheffield Wednesday in September 1999 when Bobby Robson was the manager.
Sean Longstaff, Dan Burn, Sven Botman, Callum Wilson, Anthony Gordon, Miguel Almiron, Bruno Guimaraes and Alexander Isak all scored.
It was a display that put to rest any questions about how Newcastle would cope with juggling the demands of the Premier League and Champions League, after drawing 0-0 at AC Milan on Tuesday.
It was United’s heaviest league loss in the club’s history, and came a week after conceding twice late in stoppage time to lose 2-1 against Tottenham.
It is likely to increase the pressure on manager Paul Heckingbottom, whose side has taken one point from the first six games.
The buildup to the game was dominated by the Blades’ tribute to Cusack, who also worked in the club’s commercial department, with a poignant eulogy followed by her mother and sister laying a wreath on the center circle.
Once the game started, things crumbled for the hosts in a 14-minute period where Newcastle ran amok.
The visitors took a 21st-minute lead as Longstaff fired in from eight yards.
Ten minutes later, Burn wriggled free of Anel Ahmedhodzic from Kieran Trippier’s corner to head home at the far post.
Botman then found space to head home a free kick and make it 3-0.
As Newcastle celebrated in front of the home end, fans threw objects onto the field, with a bottle hitting Elliot Anderson on the leg.
Newcastle got its fourth 11 minutes after the interval as Wilson headed home yet another Trippier assist, with both players left in plenty of space.
It was 5-0 just after the hour mark when Gordon cut inside and curled a 20-yard shot into the bottom corner.
Almiron scored the sixth by firing into the bottom corner after Guimaraes’ incisive through ball played him in.
Guimaraes then added a seventh in the 73rd when he converted a loose ball before substitute Isak completed the rout by latching on to a loose header from Tom Davies