NEWCASTLE UTD RESERVES: Sodenberg, Nicholson (Campbell 46), Folan, Streete, Henderson, McDermott, Newton, Inman, Ameobi, McLaghlin, Nzuzi. Subs not used: Riley, Alnwick, Hoganson.
Wanderers surged into a commanding 4-0 half-time lead, but Peter Beardsley’s shellshocked side fought back after the break as the 10 men tired and Bolton were forced to hold on at the end.
Adam Blakeman handed John Henry’s youngsters a seventh-minute lead when he swept home O’Halloran’s low cross.
Elliott Dennis was then sent off for a professional foul on 14 minutes after the defender brought down Bradden Inman.
But Tom Eaves took advantage of a poor clearance from goalkeeper Ole Soderberg to grab his third goal in two games.
Newcastle’s Stephen Folan rattled the crossbar from a corner but Wanderers broke quickly to add a third on 34 minutes. Marcos Alonso picked out Eaves with a fabulous crossfield ball and he squared for O’Halloran to tap in.
The Scot then rifled home his second to put Bolton well in control at half time.
Samuel Ameobi, the younger brother of Shola, pulled one back for the Magpies on 54 minutes - and Inman made it 4-2 a minute later.
Sub Adam Campbell set up a nervy finale but Wanderers held on for only their second league win of the season.