A very tight first half saw Welsh convert an early penalty before two really classy tries first by Watkins and then Lane saw the Reds go ahead 3-12.
As the half progressed the Welsh scrum started to get an edge over the Reds and two driving maul tries followed, and London Welsh went in 18-15 at half time thanks to a late penalty kick.
Jersey started the second half brightly and took an easy penalty to level the scores before Welsh scored their third try of the afternoon.
No further scores came, and Welsh also saw out 10 minutes when down to 14.
A losing BP is all that the Reds can take away from their trip to the capital.
Full report here