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Sunderland went ahead 31 minutes into its match through a Zak Swanson own goal and never looked back.

It was an unfortunate moment for Swanson, who was in the wrong place at the wrong time when team-mate Jordan Williams’s clearance rebounded off him into the goal.

Republic of Ireland international Alan Browne added a second, his first since signing for Sunderland in the summer transfer window, six minutes into the second half, before Romaine Mundle made it 3-0 and killed the game as a contest in the 56th minute.

Portsmouth made four substitutions on the hour, including the introduction of deadline-day signing Mark O’Mahoney, but none were able to get their team back into the match.

The hosts managed just one shot on target before Luke O’Nien’s stoppage-time own goal gave them a consolation. They await their first victory of the campaign and sit 18th in the table.

Oxford United went up alongside Portsmouth, but enjoyed its afternoon a little more as it came from behind to beat Preston North End 3-1 at Kassam Stadium.

It was a first defeat for Preston manager Paul Heckingbottom, who was appointed earlier in the month after Ryan Lowe was sacked.

The visitors started better, with Emil Riis Jakobsen opening the scoring after just three minutes. But in-form Mark Harris levelled after 20 minutes with a header as he scored for the fourth straight league game.

It was to get even better for Oxford in the second half when Tyler Goodrham put it into the lead with a spectacular strike.

Preston was then reduced to 10 men, with Liam Lindsay picking up a second booking in the 70th minute, and Greg Leigh wrapped up the points a minute later.

The win takes Oxford to eighth, while Preston is in 21st, one place below Sheffield Wednesday, which was beaten 3-0 by Millwall at The New Den.

Josh Coburn scored on his debut for the hosts in the second half, before goals from Duncan Watmore and Jake Cooper secured Millwall’s first win of the season. For Wednesday, it’s now three straight defeats.

Unbeaten Leeds United went fourth on the table after a 2-0 victory over Hull City, which sits 19th and is still waiting for a first victory of the campaign.

Second-half goals from Mateo Joseph and Joel Piroe at Elland Road helped Leeds secure back-to-back victories for the first time this season.

In the early kick-offs, Middlesbrough picked up a first league win since the opening day of the season as it beat Cardiff City 2-0 on the road.

A second-half header from Matt Clarke and an Aaron Ramsey own goal secured the points for Michael Carrick’s side, although Ramsey did hit the post for the hosts. The win leaves Middlesbrough sixth, while Cardiff is bottom.

Norwich City also claimed its first three points of the season with a 1-0 victory away to Coventry City.

Borja Sainz scored the winning goal after 49 minutes, with his shot taking a big deflection to wrong-foot the goalkeeper before landing in the goal.