Ronnie McFall pointed to key moments in the game that went against his Portadown team which proved to be the difference between victory and Boxing Day derby defeat.
The Ports manager highlighted a couple of missed chances, as well as two crucial refereeing decisions, that he believes cost the Ports before Rhys Marshall's dramatic injury-time winner gave Glenavon the points.
Marshall did what Gary Twigg and Mark McAllister couldn't as he headed home Gary Hamilton's corner inside the six-yard box.
Twigg had missed the target at the same end after just six minutes and right at the end of the first-half Ports players surrounded referee Ian McNabb, claiming that Glenavon defender Kyle Neill had handled in the box, but the protests were waved away.
McNabb then pulled out his yellow card twice to Portadown midfielder Michael Gault inside four minutes, leaving the Ports to play the last 24 minutes with 10 men.
They couldn't even throw Tim Mouncey in to shore up the midfield as the substitute was sent off for comments made to a linesman.
Glenavon dominated possession after that, but it was Portadown who missed the most gilt edged chance, when McAllister headed Ross Redman's cross over the bar from close range with just 10 minutes to go.
"We had a penalty kick in the first-half," said McFall.
"It was blatant and we didn't get it. It was as black and white as that - no question about it.
"Michael Gault's first booking was justified, there's no doubt about that. I thought for the second one he just slipped in the conditions. It certainly was a foul, but I didn't think in any way it was a yellow card.
"They obviously complained and went to the referee.
"I thought the officials were very poor. I thought at one stage he (referee McNabb) lost it.
"He has to take into account the conditions. Players couldn't keep to their feet and he has to take that into account. I think that's what happened to Gault for the second booking - he couldn't keep to his feet and he fell."
The Ports also lost Gary Twigg to injury after just 24 minutes, with McAllister replacing him after a spell out injured himself.
Glenavon then lost Neill, with an injury that could end his season and also put the 37-year-old's future in doubt.
"When you're down to 10 men you're going to be under a bit of pressure, but they never created much," said McFall.
"Gary Twigg had a great chance in the first-half, Mark McAllister should have won it for us late on. He'd only the keeper to beat and he headed it over the bar. Those were the key moments in the match."
GLENAVON: Tuffey, Marshall, Dillon, Kelly, Neill (McGrory 61 mins), Hall (Patton 82 mins), Kilmartin, Sykes, Cooper (Hamilton 62 mins), Bradley, Kearns.
PORTADOWN: Miskelly, O'Hara, Breen, Oman, Redman, Casement, Garrett, Gault, Mackle, Twigg (McAllister 25 mins), Murray.
Man of match: Mark Sykes
Match Rating: 6/10
Referee: Ian McNabb (Newtownabbey)