O'Driscoll was taken off injured moments later - that being played down by O'Connor - while 17 points from the boot of Ian Madigan were equally important.
Munster led 12-6 at half-time but six eventual penalties from Ian Keatley weren't enough with Leinster now five points clear of them at the top of the RaboDirect PRO12 table.
And Leinster coach O'Connor played up the importance of the result with four matches of the regular season remaining before the play-offs.
"The four points are huge. It puts us in pole position in the league which is our bread and butter and it's hugely important to the whole organisation," he said.
"There were a lot of things at play and we came out on the positive side of the ledger on most of them. Brian just got a bang on the neck.
"He was over the ball and he got his neck twisted, but he'll be fine. Cian [Healy] was really close to playing in the morning. I'd be very surprised if he doesn't take to the field next week."
Follow us on Facebook, join the conversation on Twitter, sign up to our YouTube channel for extensive match highlights and sign up for our newsletter for regular updates on the RaboDirect PRO12
Guinness PRO12 Leinster News
63x46.png){kind=logo}