It was little more than Swansea deserved after dominating much of the game with Nathan Dyer particularly impressive on the wing.
Leicester pressed for an equaliser in the second half but Lloyd Dyer and Dany N'Guessan squandered good opportunities.
The result continued Swansea's promotion push and lifted them into fourth place at the expense of Leicester who slipped out of the play-off places and into seventh.
Swansea manager Paulo Sousa made four changes to his starting line-up from the FA Cup defeat, with Angel Rangel, Federico Bessone, Leon Britton and Dyer all returning.
Nigel Pearson made three changes from his Leicester side that drew with Ipswich last weekend as Jack Hobbs, Paul Gallagher and Yann Kermorgant all came into the starting line-up.
Leicester had the first meaningful chance of the match when Gallagher got away down the right and whipped in a fine cross that was flicked into the path of Matty Fryatt, who volleyed well wide when he should have done better.
The home side duly responded with Bessone and Darren Pratley both trying their luck from distance but neither effort troubled Chris Weale in the Leicester goal.
Dyer was causing the Leicester defence problems with his pace and he cut inside Michael Morrison before firing a weak effort just wide.
Swansea deservedly took the lead with 32 minutes gone when an excellent ball from Pratley found Dyer and he burst towards the byline before cutting the ball back for Pintado to volley home.
With half-time approaching Swansea were looking like doubling their lead and Pratley took advantage of a slip from Morrison before curling an effort just wide.
Leicester pressed forward at the start of the second half in search of an equaliser and had claims for a penalty rejected after Fryatt's shot appeared to strike Alan Tate's arm.
Swansea continued to look dangerous and Pintado had another goalscoring chance when he met David Cotterill's cross but did not connect properly with the volley.
Pearson duly responded, sending on Steve Howard and Martyn Waghorn to bolster the attack, and Howard almost set up the equaliser moments after coming on.
Pratley played a poor pass straight to Howard who set up Dyer but he was unable to hit the target.
Late on Waghorn sent a cross-shot across goal and into the path of N'Guessan who side-footed wide with the goal gaping as Swansea held on.