Despite losing four starters to Origin duty, the visitors battled back to trail 22-18 and were threatening to severely dent the Warriors' finals ambitions.
"They went through that period and I thought they had the momentum in a big way,'' McClennan said. "They were winning territory with their kicks and they were playing a bit fast for us.
"I thought, `jeez, we're in trouble'.''
His players, though, evidently shared none of that apprehension, showing a maturity and direction that has been largely lacking this campaign. Once their opposition finally ceded territory, the Warriors didn't snatch at the chance but played patiently and built pressure through four repeat sets of six.
The Cowboys' tackle count rose and the strain eventually told, with Nathan Friend darting over from dummy-half to all-but clinch the crucial two points.
"What I was really pleased about was, once we got our chance with some good ball we stayed mature with it all,'' McClennan said. "We got four repeat sets in a row and we ended up breaking the ice and got a flood of points.
"That's where we want to head with our team - to stay nice and calm with it and make sure that we keep pressure on when it becomes our turn to have a bit of momentum.''
Simon Mannering denied the memories of the Sharks' game entered his head when the going got tough but said he almost expected the Warriors' woes of recent weeks to repeat, even in the early stages when the depleted Cowboys were of no match for some clinical attacking play.
"At the start of the game we were going pretty good but we knew it wasn't going to last for the whole game,'' he said.
"They're a side that were always going to come back - it was just a matter of, when they did, making sure that we matched them.
"We sort of let off a bit and let them back in it but we knew if we just got back into the swing of things that good things would come off the back of it.''
It was no coincidence those good things arrived about the same time as Friend and Feleti Mateo returned from the interchange bench. Both played a key role in the Warriors' fast start before spending a significant portion of the Cowboys' comeback on the sidelines, only to return when they game was in the balance.
Friend, fresh off a six-week absence due to a broken jaw, impressed his coach with a lot of unnoticed work, while Mateo had a hand in almost everything good in the Warriors' first half.
''[Mateo's] first stint was very good and we had a lot of ball,'' McClennan said. "We had him off the field when it was that stint when we had to do a lot of the tackling. When he came back on he sparked it up a bit for us, as did Nathan Friend.
"I thought when he came back on the field he was very good for us, too. A lot of it gets lost - he does a lot of work defensively that helps keep us tight around the ruck area.''
That work - and the game-sealing try - saw the Warriors back within two points of the top eight ahead of their trip to the Gold Coast next Saturday.
