Stephen Murray scored twice against his former club as newly-promoted Portadown beat derby rivals Glenavon 4-2 at Mourneview Park.
Murray gave his side an early 2-0 lead as they returned to the top flight after a three-year absence.
Peter Campbell pull one back for the hosts after the break before Lee Bonis restored the Ports' two-goal cushion.
James Singleton headed in a late corner but Portadown substitute Aaron Burns added a fourth in injury time.
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Murray's opening goal for Matthew Tipton's Championship winners came in the seventh minute when Ben Guy got on to a searching ball down the left channel by Chris Lavery.
Guy deliver a low cross and home goalkeeper James Taylor, deputising for Jonny Tuffey, slipped to allow the ball to reach Murray, who tapped home at the back post.
Another Lavery pass in the 31st minute set up Murray's second, with the former Warrenpoint forward running off Colin Coates and composing himself before delivering a stylish finish under the onrushing Taylor.
Matthew Snoddy was well off target with a 20-yard shot just before the home side's best effort of the first half in the 44th minute, with Campbell delivering a dangerous low cross that Paddy McNally did well to clear.
Conor McCloskey was a half-time substitute for Glenavon and his pinpoint low cross from the right in the 54th minute left Campbell with an easy finish from close range.
Campbell had a header superbly cleared off the line by Greg Hall before a Portadown counter-attack saw Murray cross for Bonis, who did well to guide his first-time shot into the top corner.
Singleton gave the home side hope when he headed in a corner on 85 minutes and Coates came close with another header, but Burns made sure of all three points for Portadown when he scored with the last kick of the game.