Ulloa, who joined the Seasiders from Almeria in January, benefitted twice from Palace's lacklustre defending, while David Lopez's excellent free-kick added the cherry on top for the home side at the Amex Stadium on Sunday.
Argentine striker Ulloa, a January signing from Spanish side Almeria, was compared to ex-Albion favourite Bobby Zamora by manager Gus Poyet this week.
And, like the QPR striker, he is already certain of a place in Brighton folklore with two derby day goals to sink their historic foes.
Much was expected of Palace's Manchester United-bound winger Wilfried Zaha and 30-goal striker Glenn Murray, who left Brighton two seasons ago. But the duo were well shackled as Brighton's frontmen instead stole the show.
Palace did almost take the lead midway through the first half - via Brighton player Matt Upson, whose diving header towards his own goal from a Yannick Bolasie free-kick forced a fingertip save from Tomasz Kuszczak.
The breakthrough came from the home side though. Brighton's first goal had a touch of fortune about it, with a left-wing cross finding the in-form Ulloa in the box. The Argentinian jumped to meet the ball, heading it onto his foot and past Palace keeper Julian Speroni to make it 1-0 ater 43 minutes.
And it was 2-0 just two minutes later, as a foul 25 yards out left Lopez with the perfect opportunity to stretch Brighton's lead. The Spaniard duly dispatched his effort over the wall and in off the crossbar to send the seventh-placed side in at the break with a two-goal cushion.
Crystal Palace failed to really accustom themselves to the game, struggling to find a foothold as Brighton asserted their dominance. Ulloa killed off any hopes of a Palace fightback as poor defending allowed him to volley home from inside the area after 50 minutes.
Ulloa could have had a hat-trick - his second in successive home matches - but was denied by Damien Delaney's last-ditch tackle and a fine save from Speroni.
But Brighton's newest hero settled for two as the Seagulls reignited their play-off bid and more importantly, as many in the record 28,499 crowd would doubtless say, got one over on the Eagles for a change.
The win leaves Brighton level on points with sixth-placed Leicester, while Palace stayed in fourth and suffered a blow to their automatic play-off hopes.