Leading 1-0 by a first half penalty, they scored twice more after the break before Upper Shirley trimmed the lead in a strong finish.
Upper Shirley made a bright start with Harry Jones, a skilful little pocket dynamo, pulling the strings in midfield.
But after the outstanding Tom Parker-Trott had made two good low saves, Wildern took the lead through Callum Esfandiari, who scored from the penalty spot after being impeded.
Knocked out of the Hampshire Under-13 Cup by Upper Shirley earlier in the season, Wildern gained the initiative and twice went close through Ollie Chambers and Nathan Jenvey.
Jones continued to sparkle and almost equalised with a cheeky over-head kick soon after the restart.
The pacey Jake Gould proved a handful for Upper Shirley and his second well taken goal put Wildern in the box seat.
Tom Parker-Trott produced a brilliant save to deny Jenvey, but could little to prevent Gould making it 3-0 with a cracking drive from the edge of the box.
To their credit, Upper Shirley didn’t roll over: instead, they produced a spirited finish, sparked by Joe Bittin’s goal.
Marco Gashi sent a glancing header just wide and Bittin was just too high as Upper Shirley produced a pulsating finish.