Four Munster players saw second-half yellow cards at the Aviva Stadium but Foley's men still battled their way to a 34-23 victory one week after going down to Ospreys at Thomond Park.
Tries from James Cronin, Robin Copeland, and Ian Keatley gave Munster a 28-9 advantage going into the break with Ian Madigan's three penalties Leinster's sole points.
The visitors' ill-discipline gave the hosts a way back into the game in the second half however, as a Darragh Fanning score and a penalty try capitalised on Conor Murray, Dave Foley, Damien Varley and BJ Botha's spells in the sin-bin.
But further penalties from Keatley and substitute JJ Hanrahan ensured Munster saw the game out and moved up to fourth place in the GUINNESS PRO12 table.
It was their first victory at the Aviva Stadium in six attempts and Foley admitted he was delighted with the way his side turned the screw on their rivals.
"Let's do what we're good at," he said. "At times we had a couple of breaches, why go away from that? If we find a weakness, let's go after that.
"We also had opportunities out wide - if the space is out wide, we'll go after that. You go after the weakness - you don't worry what it looks like to anybody else. It's what's valuable for you in that moment.
"Discipline is always a concern. If it's going your way, you take the rub of the green. If it's not, you batten down the hatches and I thought we did that very well.
"Full credit to the boys - I thought they acquitted themselves well and the physicality was excellent. We weren't perfect tonight though and there will be things we'll need to go away and work on."
Click here for the best images from Munster's 34-23 victory over Leinster.
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