He won the ball from sky blues player boss Gary McAllister to hit a strong shot under Arphexab and give West Ham's huge travelling contingent something to cheer about.
But they weren't so happy when Michael Doyle put a low cross into the box for Graham Barrett to slot home.
Brian Deane, making his debut after sigining on free transfer from Leicester midweek, had a shot and a header saved in what was, for him, a lively first half.
In the second half, Jermaine Defoe and Matthew Etherington looked likleist to score but Arphexab, who will be disappointed with the goal he conceded, was equal to them.
That said, it looked as if Patrick Suffo would give Coventry all three points, but he shot wide, having got behind the West Ham defence.
Amongst those missing were Don Hutchison with a calf injury, and Micheal Carrick with a hip problem.