The Reds ran out 4-1 winners and were the better side for long periods in the game, even if the first 45 minutes failed to yield more than a smattering of goal-mouth action.
Indeed, it took until the 50th minute for a net to bulge, as half-time substitute Michael Owen kept his cool to slot into the far corner when confronted by the onrushing Bobby Shuttleworth.
Before then, Wayne Rooney and Dimitar Berbatov missed presentable chances in the opening period, and starting Revs goalkeeper Matt Reis made two fantastic reflex saves. That action largely came in the last five minutes of the first half - before that, both teams lacked penetration in the final third and rarely tried their luck from distance.
Another of Sir Alex's second-half substitutes, Federico Macheda, made it 2-0 three minutes after Owen's opener with an equally composed finish before adding a third, and his second, on 61 minutes by lashing a shot into the far corner after Rafael's cross had eluded a crowd of players inside the penalty area.
By that time, New England Revolution, managed by former Liverpool player Steve Nicol, had pulled a goal back somewhat fortuitously. Benny Feilhaber's free-kick deflected in off his team-mate Kenny Mansally, with Reds goalkeeper Anders Lindegaard cruelly wrong-footed.