United found themselves behind almost immediately after a snap volley was palmed away by David de Gea, only for the Reds defence to fail to clear their lines and Marquinhos to creep in to find the bottom corner of the net.
The reds had settled poorly and were off the pace as they tried to get a foothold in the game. Adnan Januzaj went the closest with a sweetly-struck instinctive volley from a loose ball following a cleared Patrice Evra cross, but couldn-t quite keep his shot under the bar.
United's equaliser came shortly afterwards however, scored by Jesse Lingard but with Wilfried Zaha having provided much of the work, using his pace and trickery to beat his man down the left before his cross, aimed for Robin van Persie at the back post, was deflected into Lingard's path for a simple finish.
United soon had the lead courtesy of some clowncar defending from Yokohama - Adnan Januzaj's free-kick towards the back post bounced off a defending centre-back due to a flap from the goalkeeper, and dribbled over the line before Ichiro could get back to make the clearance.
United were now well on top, and Janzaj came close to a fifth when his curling effort from just outside the area was pushed around the post by the keeper. The youngster continued to be involved in United's attacks, showing a brilliant touch shortly after only to overhit his pass for Van Persie, before leading United's last attack of the half.
It was a poor start, but the Januzaj-Zaha-Lingard trio looks highly promising indeed. We'll see where Shinji Kagawa fits into Moyes' plans in the second half, and should see some other introductions too.