Offaly went in at half time level with Clare in O'Connor Park despite being on the back foot for most of the opening 35 minutes.
Having begun well, Offaly started to lose the midfield battle midway through the half, allowing for a spell of Clare dominance.
They led by four nearing injury time but a rallying point from Johnny Moloney on 34 minutes sparked a Faithful revival.
From the next attack Ruairi McNamee was hauled down in the square and an unlikely penalty taker emerged from down the field.
Walsh Island goalkeeper Mulhall, known for his penalty blasting exploits at club level, marched forward and without a shred of fuss, buried his effort to the back of the net deep in first half injury time.
At half time, the scoreline reads Offaly 2-5, Clare 1-8.
You can watch the glorious clip of Alan's goal at the head of this article.