However, this proved to be a false dawn as the rest of the half was mostly uneventful, apart from the goal which gave Clyde their narrow interval leader.
A cleverly-flighted free-kick split the Airdrie central defensive partnership and allowed the lively McGowan to cut in between them to score with a low shot from about 12 yards.
Airdrie replaced Stephen McKeown by Willie McLaren at half-time and the visitors began to take control. McLaren's first contribution from a corner picked out midfield colleague Stephen Docherty as he burst into the danger area, but unfortunately his first- time volley was just wide of the upright.
Docherty came closer still when he got his head to a Brian McPhee knockdown only to be denied by the base of the post.
Luck was against him yet again as he rattled the crossbar with a drive from outside the penalty box.
Clyde had chances of their own to put the match beyond doubt but couldn't put them away. Airdrie were denied a share of the points when Robert Harris became a home hero when he made sure of a Clyde victory by kicking an Allan McManus effort off the line in the third minute of injury time.