Two goals 40 seconds either side of half-time proved fatal to Sunderland after the Premier League’s basement boys went down 3-0 at Manchester United.
Sunderland had produced a much-improved display of defensive disclipine at Old Trafford and were growing in confidence, when they conceded in first-half stoppage time and could never recover, to leave the search for a top-flight win continuing.
Memphis’s opening goal was followed by another straight after the restart when Wayne Rooney left the hosts with a comfortable two-goal cushion.
Sunderland had chances to get back in the game, but they were spurned by Ola Toivonen and then Patrick van Aanholt, to allow Louis van Gaal’s side to slip into cruise control.
Juan Mata added a third in the last minute, to extend Sunderland’s winless start to the season to seven games.
Sunderland made four changes from the midweek Capital One Cup defeat, with Costel Pantilimon, Younes Kaboul, Lee Cattermole and Billy Jones returning to the starting XI at the expense of Vito Mannone, Sebastian Coates, DeAndre Yedlin and the injured Jack Rodwell.
Despite United predictably dominating possession, Sunderland began the game solidly - the hosts having to wait until the 13th minute for their first real sight of goal when Juan Mata sent a deflected shot just wide from the edge of the box.
Sunderland had a chance themselves at the midway point of the half when Yann M’Vila lifted a lovely ball down the right-hand channel for Jeremain Lens to run onto.
It was a tight angle for Lens, but he let fly with a right-foot half-volley which was pushed away by the legs of David De Gea.
At the other end, Memphis then saw a curling shot from 20 yards tipped over the bar by Costel Pantilimon.
But at the end of a tepid first half, United broke the deadlock just 30 seconds before the interval after the Sunderland back-line were caught out by a perfectly-floated ball over the top from Danny Blind.
Mata managed to get on the end of it and knocked it back into the path of Memphis, who got to the loose ball ahead of Billy Jones to tap into the net.
Dick Advocaat made a change at the interval with Steven Fletcher taking the place of Adam Johnson, with Borini moving to a wide midfield role.
But it took United just 40 seconds of the second half to double their advantage after Anthony Martial ghosted past Younes Kaboul down the right-hand side of the area, crossed low and Rooney managed to divert it beyond Pantilimon off his knee.
Sunderland should have got a way back into the game in the 54th minute though after spurning a gilt-edged opportunity to get on the scoresheet.
United failed to deal with M’Vila’s inswinging free-kick from the left, it came to John O’Shea and Ola Toivonen a couple of yards out, but the latter’s stab at goal was saved by the legs of De Gea.
Sunderland had another opportunity just after the hour mark when Cattermole bisected the United defence with a lovely diagonal pass to pick out the run of Patrick van Aanholt.
The left-back burst down the left-hand side of the area, but made too narrow an angle for himself and when he delivered a shot, it was realtively comfortably saved by the outstretched leg of De Gea.
But United could have been out of sight in the 68th minute when Kaboul - as at Bournemouth - was far too eager to intercept and allowed Martial a run in behind him.
With a two-on-one, Martial freed Memphis, but with only Pantilimon to beat, the Dutch winger’s tame shot was saved well by the Sunderland keeper.
Pantilimon then had to produce a brilliant finger-tip around the post to keep out Mata’s low shot from the edge of the area.
Mata wasn’t to be denied though, and in the last minute he grabbed United’s third when he tucked Young’s low left wing cross into the net at the far post after being given far too much room by van Aanholt.
Manchester United: De Gea, Valencia, Smalling, Blind (Jones 74), Darmian, Carrick (Schweinsteiger 68), Schneiderlin, Mata, Memphis (Young 77), Rooney, Martial. Subs not used: Romero, Herrera, Fellaini, Pereira.
Sunderland: Pantilimon, Jones, O’Shea, Kaboul, van Aanholt, Cattermole, M’Vila, Toivonen (Larsson 70), Johnson (Fletcher 46), Lens, Borini. Subs not used: Mannone, Coates, Gomez, Yedlin, Defoe. Booked: Johnson (38), Jones (50), Cattermole (85)