The result moves Lazio five points ahead of Catania in the race for European places and avenges a 4-0 drubbing by the Elefanti, back in November.
Catania were without suspended duo Nicolas Spolli and Alessandro Potenza and injury victim Sergio Almiron.
Lazio put Catania under the cosh from the first whistle, forcing the initiative with a plethora of early corners.
Candreva proved to be a handful throughout the first 45 minutes. His run into the box and subsequent shot stung Mariano Andujar's palms on nine minutes. A Cristian Ledesma free kick almost deflected in off Giuseppe Bellusci five minutes later.
Saha somehow missed a chance from four yards out after the ball ricocheted off a Catania defender and into the Frenchman's path. Saha swept the chance across the face of goal with Andujar already on the ground.
On 24 minutes, Andujar flew to punch clear a dangerous Candreva cross. Just before the half hour mark, a series of intricate passes released Lorik Cana into the box. Giovanni Marchese charged him down, but the ball flew into the air and struck the crossbar, with Legrottaglie having to run across to volley the ball clear.
Another dangerous Candreva ball was cleared before Senad Lulic could pounce. The winger clearly had the bit between his teeth, as he fizzed another effort off Andujar's gloves.
Catania finally sauntered forward five minutes before the break, but a weak Pablo Barrientos cross was easily smothered by Federico Marchetti. Right on half time, Saha misjudged a jump as he failed to meet a Hernanes corner at the far post.
With all Lazio's domination, it seemed ironic that Catania would hit the front five minutes into the second half. Stefan Radu's clearance ricocheted off of the boot of Izco and looped over Marchetti into the empty net.
The hosts were shell-shocked and took a while to recover. In his final contribution, Saha headed a corner down into Andujar's arms. Libor Kozak and Ederson were thrown on to freshen up the home side's attack. Ederson teed up his Brazilian counterpart Hernanes to fire over from 30 yards.
The substitutes almost combined for an equaliser on 69 minutes. Ederson dribbled around several Catania players into the box and stabbed the ball to Kozak, but Marchese slid in to deny the Czech striker from four yards.
Klose was introduced for the final 15 minutes and Lazio were infuriated not to be awarded a penalty when Pablo Alvarez brought Kozak down in the box. Cristian Ledesma was booked for taking his protests too far.
The equaliser finally came on 79 minutes. Radu's first time cross was turned into his own net by Legrottaglie, as the defender tried to intercept Kozak. Moments later, Lazio did receive a penalty after Bellusci barrelled into Ederson. Candreva coolly sent Andujar the wrong way as he stroked his spot kick into the bottom right hand corner.
Barrientos and Marchetti were both booked in stoppage time after tempers were raised from a foul throw. Barrientos hit a shot at goal after the referee pulled play back, having previously not been able to hit a cow's backside with a banjo all afternoon.
Lazio: Marchetti; Gonzalez, Biava, Cana, Radu; Candreva, Onazi, (Ederson 63) Ledesma, Hernanes, (Klose 75) Lulic; Saha (Kozak 63)
Catania: Andujar; Alvarez, Legrottaglie, Bellusci, Marchese; Izco, Lodi, Biagianti; (Doukara 86) Barrientos, Bergessio, Gomez (Castro 78)
Goals: Izco 50 (C) Legrottaglie OG 79 (L) Candreva pen 81 (L)