Welka fired home five minutes into the second half after Simon Lenighan had given the Elland Road visitors the first-half advantage.
A crowd of 580 saw the hosts more than match their opponents, who fielded a youthful side with some first-team squ
ad members including Alan Sheehan thrown in.
And Hemsworth almost got off to a superb start when Tom Grindel saw his effort well saved by Leeds goalkeeper Christian Briggs.
Chances came at both ends in an entertaining first-half but it was the visitors who broke the deadlock.
A Sheehan free-kick was parried by MW stopper Adam Tasker and Lenighan reacted quickly to tap in the rebound.
Welka's superb 25-yard strike got the hosts on level terms five minutes after the restart.
Both sides looked for a winner but defences remained on top for the rest of the match.
MW are back in friendly action next Tuesday when they host Skelmanthorpe, kick-off 7.30pm.
Hemsworth Reserves host Altofts on Saturday, kick-off 2.30pm.
See Thursday's Hemsworth and South Elmsall Express for all the latest sports news from around the area.