The Sheffield Wednesday striker, on loan until January, shot home from eight yards into the bottom corner.

Gary Richards was the player sent off after a rough challenge on Oldham striker Craig Davies.

The nearest the Latics came to an equaliser was when Neal Eardley saw a 20-yard pile driver hit a post and Matt Wolfenden curled a shot just over.

Oldham: Crossley, Hazell, Thompson (Eardley 46), Gregan, Bertrand, Liddell, McDonald (Wolfenden 81), Allott, Taylor, Davies, Hughes (Ricketts 65).
Subs Not Used: Bell, Kalala.

Booked: Hughes, Davies.

Southend: Collis, Hunt, Peter Clarke, Richards, Barrett, Black (Wilson 45), Maher, Bailey, McCormack, Leon Clarke (Foran 81), Harrold.
Subs Not Used: Gower, Hooper, Odhiambo.

Sent Off: Richards (45).

Booked: Leon Clarke, Harrold, Hunt.

Goals: Leon Clarke 28.

Att: 5,151.