Meath produced a stirring comeback at Ruislip to book their place in the semi-finals.
The Royals trailed by five points with 20 minutes left but outscored London by 1-7 to 0-1 from there. Gavin McGowan pounced for a goal on 63 minutes to give Meath the lead and they added two late points as the Exiles wilted.
Martin Duggan's goal had put London in command on the half hour
But Meath's response was immediate, Adam Gannon producing a wonderful catch and finish to leave it 1-10 to 1-8 at the interval.
Kevin O'Loughlin and Kevin Reid firing the exiles into a five-point advantage, but the scores then dried up for London.
Meath chipped away at London's lead and moved in front when high ball was broken down in the area and although Neil Heffernan was denied by keeper Eoin Kelly, McGowan was on hand to fire home the rebound.