Josh MacDonald had a hat trick for the Petes (20-21-4), who extended their win streak to four games, while Nick Ritchie tacked on three assists.
Ryan Van Stralen scored twice and added an assist for the 67's (15-25-4) and Brett Gustavsen and Erik Bradford had a goal apiece.
Peterborough's Andrew D'Agostini made 30 saves for the win as Ottawa's Liam Herbst gave up seven goals on 36 shots.
Petes' forward Jonatan Tanus was ejected at 13:59 of the first period after receiving a check-to-the-head major.
STEELHEADS 3 KNIGHTS 1
MISSISSAUGA, Ont. — Spencer Martin kicked out 38 shots, including 18 in the second period, as the Steelheads downed London.
Stefan LeBlanc, Sean Day and Brett Foy supplied the offence for Mississauga (17-26-4).
Gemel Smith scored for the Knights (29-11-5), who have dropped back-to-back contests.
London's Jake Patterson turned away 27-of-30 shots in a losing cause.
BATTALION 5 ICEDOGS 1
NORTH BAY, Ont. — Nick Paul had a pair of goals and Jake Smith made 20 saves as the Battalion toppled Niagara.
Matt Gillard scored the lone goal for the IceDogs (15-24-6) midway through the third period to stop Smith's shutout bid.
Blake Richard stopped 37-of-42 shots for Niagara.
GREYHOUNDS 4 ATTACK 2
OWEN SOUND, Ont. — Jorgen Karterud had a goal and an assist as Sault Ste. Marie doubled up the Attack for their sixth win in a row.
Tyler Ganly, Bryan Moore and David Miller also scored for the Greyhounds (32-10-5), who lead the West Division.
Kyle Hope and Daniel Milne responded for Owen Sound (21-18-6).
Matt Murray made 25 saves for Sault Ste. Marie while Brandon Hope turned aside 38-of-42 shots for the Attack.
GENERALS 5 STING 2
OSHAWA, Ont. — Hunter Smith had two goals and an assist and Bradley Latour set up four goals as the Generals beat Sarnia.
The Sting (14-26-5) got goals from Nickolas Latta and Ryan Vendramin.
Daniel Altshuller only had to make 12 saves for the Generals while Taylor Dupuis stopped 36-of-40 shots for Sarnia.
SPITFIRES 3 WOLVES 1
WINDSOR, Ont. — Brady Vail had a goal and two assists as the Spitfires won their third straight by defeating Sudbury.
Trevor Murphy and Sam Povorozniouk also scored for Windsor (27-17-2) while Josh Ho-Sang had two assists.
Nathan Cull was the lone scorer for the Wolves (25-12-7), who have dropped back-to-back games.
STORM 6 FRONTENACS 1
GUELPH, Ont. — Zack Mitchell scored twice and Josh Nichols made 38 saves as the Storm breezed past Kingston for their sixth straight win.
Matt Finn, Zac Leslie, Brock McGinn and Scott Kosmachuk also scored for Guelph (35-8-3), which jumped over the Erie Otters for top spot in the Midwest Division, while Kerby Rychel and Jason Dickinson each chipped in with three assists.
Spencer Watson scored a late goal for the Frontenacs (24-17-4), who are on a five-game slide.
Kingston's Matt Mahalak stopped 44-of-50 shots in defeat.