Rogers recklessly hauled down ex-Iceland international Tryggvi Gudmundsson five minutes into the second half for IBV captain Andri Olafsson to calmly send the keeper the wrong way from the spot.
Rogers, though, redeemed himself with two terrific saves inside a minute.
First Denis Sytnik’s curling effort from 20 yards looked destined for the far top corner before Rogers clawed it away one-handed.
The danger remained from the corner which wasn’t properly cleared and Ugandan Tonny Mawejje’s stinging shot was again turned out by Rogers at full stretch again for IBV’s ninth corner of the game.
St Pat’s pressed hard for the rest of the game and created enough chances to have at least got an equaliser, most notably four minutes from time when substitute Anto Murphy’s header from a Stephen Bradley corner was headed off the line by Mawejje.
Then, right on 90 minutes, defender Brian Shortall headed wide after IBV failed to clear Murphy’s long throw.
“We had enough chances to have got an away goal. We should have at least got one or two,” reflected Pat’s manager Pete Mahon last night.
“I believe we’ll definitely take them at home,” a defiant Mahon added.
Though unsure in defence, IBV were a threat attacking, forcing six corners to nil in the first half. Veteran striker Gudmundsson signalled that intent getting in behind on 11 minutes to cross. Derek Pender defended well to clear with Sytnik lurked behind.
That raised the home side’s confidence and they caught the Saints square on 18 minutes. Central defender Rasmus Steenberg Christiansen’s long diagonal ball dropped between Shortall and left-back Ian Bermingham. But St Pat’s were thankful right-back Kelvin Mellor’s finish was shocking as he sliced wide.
St Patrick’s captain Bradley’s direct free-kick bringing the opening save of the night from Albert Saevarsson.
Saeversson had a more comfortable stop from Danny North’s first sight of goal on 35 minutes.
A minute later Pat’s ought to have been ahead. Bradley’s delightful chip put Kavanagh in on goal but the finish lacked composure as he volleyed over.
IBV were exposing worrying cracks in the St Patrick’s defence now and Rogers had to get down well to his left to hold a drive from Sytnik after Mawejje set him up.
The game then turned within a minute early in the second half.
A mistake by Eidur Sigurbjornsson gave Kavanagh a run on goal. Stretching, he toed narrowly wide.
Seconds later at the other end, Rogers was adjudged to have taken down Gudmundsson and Danish referee Michael Svendsen gave the penalty.
Saevarsson; Mellor, Sigurbjornsson, Christiansen, Garner; Mawejje, F. Olafsson, Vladimarsson; Sytnik (Thorarinsson, 73 mins.), A. Olafsson (Hughes, 78 mins.), Gudmundsson (Borgthorsson, 85 mins.).
Rogers; Pender, E. McMillan, Shortall, Bermingham; Bradley, Crowley (McFaul, 61 mins.), Mulcahy (Murphy, 84 mins.); Kavanagh, North (Daly, 75 mins.), Doyle.
Referee: Michael Svendsen (Denmark)