A late strike from 20-year old forward David Poole gave United victory at the County Ground. His 82nd minute winner meant that the Wanderers will be relying on results elsewhere if they are to stand a chance of progressing to the final.
Co-incidentally United have already booked their place in the final due to this result and could either face either Manchester City or Bolton in a few weeks from now.
Midfielder Lee Martin, no relation to the 1990 FA Cup final goalscorer, gave United the lead shortly before the break but the former Lyon centre half Laville levelled things up for Wanderers with a header in the early stages of the second period.
Bolton keeper Sam Ashton produced a couple of good stops throughout the second half of the game, but was unable to do anything about the winning goal from Poole at the death.
Neil McDonald will be disappointed to see his Bolton team lose their 100% record in this competition but will be hoping that they gain some revenge over United in Thursday's FA Premier Reserve League match at Moss Lane.
BOLTON RESERVES: Sam Ashton, Rhys Powell, Charlie Comyn-Platt, Florent Laville, Jaroslaw Fojut, Blessing Kaku, Craig Knowles (Luke Magill), Robert Sissons (Danny Stott), Bedi Buval, Duong Thach, Jamie Gibb (Karl Luisi)
SUBS NOT USED: Michael Gillan, Przemyslaw Kazimierczak (GK)UNITED RESERVES: Tom Heaton, Philip Picken, Adam Eckersley, Jonny Evans, Steven Hogg, Richard Jones, David Poole, Lee Martin, Kenny Cooper, Mads Timm, Ben Collett.