A Stewart Kean penalty was enough to ensure three points for Saints against a Brechin side who suffered double misfortune: Grant Johnson was harshly sent off and Craig McEwan missed a late penalty.
The first 12 minutes were uneventful; then Saints turned up the heat. Alan Reid volleyed wide a Billy Mehmet cross and Simon Lappin just couldn't climb high enough to capitalise on another Mehmet cross.
Lappin's cross from a short corner was met with a glancing header by Mehmet, but Kean's cut-back from the goal-line found no Saint to take advantage.
Brechin were limited to some neat midfield possession, and Darren Smith's long-range shot was easily saved by Chris Smith, a last-minute replacement for Craig Hinchcliffe, injured in the warm-up.
Craig Nelson fumbled a Reid header, but ex-Saint Scott Walker cleared as David van Zanten swooped. Kirk Broadfoot came close with a blistering low drive which swept just wide of Nelson's left-hand post.
Seven minutes from the break van Zanten was hauled down by Johnson and Kean slammed the penalty kick high past Nelson. The luckless Johnson was given a yellow card for the foul then received another on half-time for a clumsy challenge on Kevin McGowne, a harsh decision by referee Stuart Dougal.
Saints had chances in the second half. Broadfoot combined with Kean but Nelson saved, a Hugh Murray header was held by Nelson and John Potter headed over.
Ten minutes from time, Kevin McGowne brought down substitute Stuart Callaghan but McEwan blazed the penalty kick high over the bar.