The Football Conference Youth Alliance encounter went the way of many others this season — with United edged out.
Birmingham led by two goals by the time Kormis cut the deficit on the hour mark.
Boston (4-4-2): Sam Vince; Niall Delahoy, Charlie Melville, Todd Devlin, Jordan Sowerby; Leon Squire (Miles Lynch 60), Aaron Eyett, Lewis Sturman, Lewis McKue (Karolis Andriulionis 74); Charley Sanders, Juris Kormis (Lemos Pereira 65). Sub (not used): Jacob Pease.