Linfield beat big two rivals Glentoran 4-2 on penalties after 120 minutes of action had failed to produce a goal in the League Cup clash at the Oval.
Glentoran's Mark Clarke was sent off in the second half after a melee had broken out in the dugout area.
John McGuigan and Jordan Hughes missed Glentoran penalties in the shoot-out as Michael Gault sealed Linfield's win.
Crusaders beat Coleraine 4-1 after extra-time while Ards beat Dungannon on penalties after the game finished 1-1.
At Seaview, Matthew Snoddy put Crusaders ahead on nine minutes but Gary Browne levelled for the Bannsiders on 40 minutes.
After the game went to extra-time, Josh Robinson nodded the Crues into the lead again on 105 minutes and Jordan Owens headed efforts on 117 and 119 completed the home team's victory.
At Stangmore Park, James Cully put Ards ahead on 17 minutes but Jamie Glackin's Swifts equaliser on 75 ensured extra-time.
After extra-time had failed to produce a goal, Chris Lavery and Ryan Harpur missed Dungannon penalties in the shoot-out and while Stephen McCullough also failed for Ards, Ben Roy's successful spot-kick sealed the North Down club's victory.
At the Oval, Linfield keeper Jonathan Tuffey made three good early saves to deny Richard Clarke, Jimmy Callacher and Calum Birney.
Tuffey then had to move smartly five minutes before the break to touch a Richard Clarke effort over the bar for a corner.
Mark Clarke was dismissed following his second yellow card on 55 minutes after a melee had broken out near the dugouts following his apparent tangle with Gault.
Clarke had been booked five minutes earlier for a late challenge on Jamie Mulgrew.
Glentoran's Marcus Kane and Linfield's Niall Quinn went close in the second period of extra-time before the game went to penalties.
Glens old boy Andrew Waterworth missed Linfield's first penalty but Glentoran substitutes McGuigan and Hughes then blazed over the crossbar which allowed Gault to seal his team's shoot-out success.
League Cup Third-Round results
Cliftonville 5-0 Dundela
Crusaders 4-1 Coleraine (aet)
Dungannon Swifts 1-1 Ards
(Ards won 4-3 on penalties)
Glenavon 4-1 Institute
Glentoran 0-0 Linfield
(Linfield won 4-2 on penalties)
Portadown 6-0 Lisburn Distillery
Ballymena United 3-0 Ballinamallard United