The Foxes eased to victory against their struggling opponents, thanks to the Argentine's brace and a Wes Morgan header, to move further away from the relegation zone
Ulloa opened the scoring after just 38 seconds at the King Power Stadium, and that set the tone for another fruitful afternoon for Nigel Pearson's side, who have now won five of their last six games to ensure their hopes of Premier League survival remain in their hands.
Captain Wes Morgan took advantage of more meek Newcastle defending to double Leicester's lead in the 17th minute, and Ulloa was on hand to convert a penalty shortly after the restart to seal a comprehensive win.
By contrast, Newcastle - whose misery was compounded as defenders Mike Williamson and Daryl Janmaat picked up red cards in the second half - were woeful once again.
John Carver's team have lost eight matches in a row and sit just a point above upwardly mobile Leicester - with the visiting supporters making their feelings towards owner Mike Ashley known throughout.
Leicester made the perfect start when Ulloa nodded them ahead in the first minute, the Argentinian brushing off the attentions of Moussa Sissoko to glance Marc Albrighton's corner beyond Tim Krul.
Newcastle responded well, with Ayoze Perez dragging a shot wide of the far post, but another excellent Albrighton set-piece - coupled with shocking marking - proved their undoing 17 minutes in.
Albrighton swung in a dangerous free-kick from the left and Morgan was on hand to toe-poke past the helpless Krul from six yards after Ulloa just failed to make contact.
That goal sparked a prolonged spell of anti-Ashley chanting from the away end, and any hope they may have had of an unlikely second-half comeback evaporated just three minutes after the interval.
Emmanuel Riviere inexplicably barged Marcin Wasilewski in the back in the area from a corner, and Ulloa stepped up to coolly fire his penalty high past Krul and end the game as a contest.
Leicester were brimming with confidence and Albrighton shot wide before Ulloa spurned a chance to get his hat-trick when Krul made a brilliant point-blank stop from his header.
Newcastle's day went from bad to worse soon after when Williamson let his frustration get the better of him, needlessly scything Vardy down to earn a second booking.
Carver's men were going through the motions - typified by Janmaat's late dismissal - and could count themselves fortunate that Leicester were not more clinical in front of goal as Albrighton and Jeffrey Schlupp caused havoc down the flanks.
The scoreline, at least, remained relatively respectable but the same cannot be said for Newcastle's attitude and they are now undeniably involved in a relegation dogfight.