Limerick secured their fifth consecutive victory of the season after a tougher than expected challenge from London at Rathkeale.
James Hynes, Tommy Clarke's free and Seán Hickey fired London into a three-point lead before Pádraig de Brún opened the home account.
Goalkeeper Donal O'Sullivan came up to equalise off a free and a '45' and Jamie Lee's free coming up to the break put Limerick 0-4 to 0-3 ahead.
They were all square when London goalie Noel Maher sent over his '45' on the restart before Lee's free, Séamus O'Carroll and Danny Neville had Limerick on control.
However, Liam Gavaghan replied with a free for the visitors and moments later Hickey had a shot which screamed wide of the post.
The sides traded score before Kevin Rafferty again narrowed the gap to one but London couldn't source an equaliser.
Scorers for Limerick: J Lee 0-3 (3f), D O'Sullivan 0-2 (1f, 1 '45'), P de Brún, S O'Carroll, D Neville (0-1 each).
Scorers for London: J Hynes, T Clarke (f), S Hickey, N Maher ('45'), L Gavaghan (f), S Nolan, K Rafferty (0-1 each).
LIMERICK: D O'Sullivan; P Maher, B Fanning, M Donovan; T McCarthy, I Corbett, B Childs; T Griffin, T Childs; P de Brún, C Fahy, S O'Carroll; J Lee, D Neville, P Begley.
Subs: J Naughton for P Begley (ht), G Stack for S O.Carroll (57), J Ryan for T Griffin (61), H Bourke for P de Brún (66).
LONDON: N Maher; P Butler, E Flanagan, C O'Neill; R Sloan, M Moynihan, E Walsh; R Forde, C O'Doherty; L Gallagher, L Gavaghan, T Clarke; C Coyne, J Hynes, S Hickey.
Subs: L Turley for R Forde (inj, 22), F McMahon for T Clarke (43), K O'Carroll for J Hynes (53), S Nolan for S Hickey (60), K Rafferty for P Butler (66).
Referee: D Murnane (Cork).