Ross County's gameplan was disrupted before kick-off when Sean Kilgannon and John Rankin both picked up injuries in the build up.
Steven Mackay replaced Kilgannon on the left side of midfield and Neil MacDonald took over from Rankin on the bench.
The Firth side took the early initiative and former Caley Thistle player Paul Sheerin forced a save from Stuart Garden in the first minute. Then Steve McConalogue curled one in at the far post which was easily held by the County keeper.
After a promising start to the match play got bogged down in midfield for long spells and it took a penalty kick in the31st minute to liven things up.
Michael Moore was taken down inside the area by MacKay and former County captain David Hannah made no mistake from the spot.
County broke on the left and Saints defender Kevin Fotheringham was forced to head over a strongly struck cross from Mark McCulloch.
But it was Saints who almost doubled their lead in the 38th minute when a stinging shot from McConalogue brought out a flying save from Garden.
At the other end Gary McSwegan's shot looked to be sneaking in, but Allan McGregor managed to touch the ball round the post for a corner.
Hesitancy in the County defence allowed Lee Hardy a clear run on goal but his finish was weak.
County brought on David Winters for Stuart Malcolm in the 55th minute as they went to a free up front, but there was Fotheringham who came close with a long-range shot that bobbled past Garden's left-hand post.
The home side were further up against it eight minutes later when McSwegan was sent off after a clash with Fotheringham.
Despite being a man down County started to play their best football and Don Cowie was unlucky with a shot that rebounded off the upright, then Mackay failed to test McGregor with a weak shot from just inside the area.
But Saints were not completely out of it and Ian Hardy brought down a full-length save from Garden, then McConalogue screwed a shot wide with the goal at his mercy.
A mix-up between Martin Canning and Malcolm allowed McConalogue a sight of goal, but Garden managed to scramble the ball away.