Right wings Tim Stapleton and Anthony Stewart converted in the shootout for Chicago (18-15-0-2), which is riding a three-game winning streak.
The win was the fifth straight for Mannino (8-2-0), who stopped 33 of 35 shots in regulation and overtime.
"It was a well earned win. We've been playing real solid and we're getting rewarded for it," said Wolves Head Coach Don Lever. "Tonight was a hard fought game and I thought it was a great game to watch. They're a hard working team but we played through it."
Peoria (19-13-1-3) got on the board first with a power-play marker form Nicholas Drazenovic at 17:57 of the first period. Mannino made an initial save but the puck rebounded into a scrum in front of the net, where Drazenovic got his stick out and sent it bouncing into the net.
The Wolves used a power-play chance to even the score, 1-1, at 2:31 of the second period. Defenseman Nathan Oystrick hammered a shot from high in the zone that sailed through traffic in front of the net where left wing Brett Sterling redirected it under Peoria netminder Ben Bishop's legs.
Bishop (12-6-2) turned aside 36 shots for the Rivermen and stopped two Wolves attempts in the shootout.
Chicago pulled ahead midway through the second period, 2-1. Right wing Anthony Stewart tore down the ice on a breakaway and ripped a shot at Bishop, which the goaltender stopped, but a Peoria player chasing the play accidentally knocked the rebound into the net.
The Wolves held a 2-1 edge with six minutes remaining in regulation before a power-play tally from Peoria knotted the game at two. Defenseman Jonas Junland fired a shot straight down the slot, which slid by Mannino, five hole.
The Wolves travel to Canada to take on the Hamilton Bulldogs at Copps Coliseum on Wed., Jan. 6, at 6:30 p.m.
Peoria 1 0 1 0 -- 2
Chicago 0 2 0 0 (1) -- 3 (SO)
First Period---1, Peoria, Drazenovic 9 (Lampman, Palushaj), 17:57 pp. Penalties---Stewart, Chicago (holding), 11:59; Oystrick, Chicago (tripping), 16:08.
Second Period---2, Chicago, Sterling 18 (Oystrick, Krog), 2:31 pp; 3, Chicago, Stewart 8 (Kozek, Kulda), 9:56. Penalties---Palushaj, Peoria (diving), 1:56; Porter, Peoria (hooking), 15:31.
Third Period---4, Peoria, Junland 9 (Lampman, Palushaj), 14:00 pp. Penalties---Richmond, Peoria (delay of game), 1:49; Sterling, Chicago (tripping), 13:17; Porter, Peoria (roughing), 20:00; Machacek, Chicago (roughing), 20:00.
Shootout---Peoria: Palushaj, made; Junland, miss; Talbot, miss; Tallackson, miss; Drazenovic, miss. Chicago: Stapleton, made; Doell, miss; Stewart, made; Sterling, miss.
Shots on goal---Peoria: 11-8-11-5--35. Chicago: 12-8-15-3-1--39. Power plays---Peoria: 2-3. Chicago: 1-3. Goalies---Peoria, Bishop (36-38). Chicago, Mannino (33-35). A---15,319. Referee---Kyle Rehman. Linesmen---Craig Kneale and Jesse Pletsch.