But seven minutes into the second half, Alan Quinlan stretched over for the game's only try and O'Gara took his place-kicking haul to 11 points as the Magners League leaders returned to winning ways.
A groin problem and subsequent complications had ruled Paul O'Connell out of Munster's plans since last March, and his most recent appearance for the province was in the Heineken Cup last January.
So it was a welcome sight for Tony McGahan to see his captain, who was introduced as a second half replacement, coming through his 25 minutes on the pitch unscathed.
Parks opened the scoring with a terrific 48-metre kick close to the left touchline, punishing Lifeimi Mafi for going off his feet at a fourth minute ruck.
Munster responded with two powerful bursts from hooker Damien Varley, who was held up over the try-line. The hosts turned down a kickable penalty in favour of a close-in lineout, but Blues lock Michael Paterson stole the throw.
Munster maintained a territorial dominance but could not trouble the scoreboard, with flanker Niall Ronan miscuing a drop goal, Varley guilty of a crooked lineout throw and a couple of passes going astray.
That pattern continued until disciplined defence from Cardiff lifted the siege and there were some nice touches from Casey Laulala and Richie Rees as the visitors gained ground.
On the half hour mark, half-breaks from wingers Gavin Evans and Richard Mustoe catapulted Cardiff towards the Munster 22, and a lovely one-handed pass from Rees sent Taufa'ao Filise rumbling towards to the posts.
From the ensuing ruck, Munster had Tony Buckley sin-binned for spoiling Cardiff ball and Parks mopped up with the simple penalty.
Munster's attacks were of the long range variety as the first half came to a close and O'Gara converted a 39th minute penalty, after he had been tackled late by Cardiff replacement Ben White, to leave three points between the sides at the break.
Within 43 seconds of the restart, the Blues were inches away from a try. Chris Czekaj launched himself down the left wing, Munster gave turnover ball back to the visitors and a diving Tom Shanklin was denied a try in the right corner by Mick O'Driscoll's left leg.
It was the signal for Munster to up their game and after a terrific leg-pumping run from Sam Tuitupou, play was switched to the left where Quinlan picked from a close range ruck and crashed over despite the presence of two Cardiff defenders.
O'Gara converted for a 10-6 turnaround and then added his second penalty for a seven-point advantage. O'Connell won a lineout immediately after his introduction which unsurprisingly drew the biggest cheer of the night.
But Cardiff kept probing and continued to look dangerous with ball in hand. Laulala clattered his way into the Munster 22 and although White was able to get his boot to a cross-field kick from Parks, it dribbled too far ahead of him and Johne Murphy got the touchdown for Munster.
Parks' third successful penalty closed the gap to 13-9, right on the hour, but as the fog closed in, Munster's forwards were able to keep things tight and exert more control.
Parks' last sight of the posts was a missed drop goal attempt, seven minutes from the finish, and O'Gara settled the issue with a straightforward 78th minute penalty.
Speaking after the game, man-of-the-match Damien Varley said: "Cardiff are a very good team, we expected a tough encounter tonight and they were very physical up front.
"The win today is good going into next week (against the Ospreys), but there are a lot of things that need to be worked on.
"Having Paul back is fantastic. The reception he got tonight was great and the players and supporters were enthused by his return."
|Munster Rugby Score Card|
|Cardiff Blues Score Card|