Newcastle Knights players after conceding a try.

Close, but not quite committed or composed enough when it mattered.

That was how Knights coach Nathan Brown summed up Newcastle’s 16-14 loss to Penrith at McDonald Jones Stadium on Saturday night.

Brown said the Panthers made the big plays in the big moments and that was the significant difference between the two teams in a grafting contest before a crowd of 19,451.

It was Newcastle's second straight nail-biter on home soil after a late Edrick Lee intercept try secured a 14-8 victory over Cronulla in their season-opener eight days earlier.

"I just thought there were a couple of key moments, and they came up with those big plays and we didn’t come up with them," Brown said post-match.

"Last week we came up with them and we beat a very good side, and this week we didn’t quite come up with them and we just went down to a very good side, and that’s pretty much where I saw the game."

Brown pointed out two pivotal plays where the Panthers were rewarded for showing more effort.

As Knights backs Connor Watson and Shaun Kenny-Dowall stood and willed Nathan Cleary’s 35th minute stab kick to go dead, a more desperate Malakai Watene-Zelezniak batted the ball back for team-mate Frank Winterstein to score and give the Panthers a 10-8 lead at half-time.

Then in the 69th minute, when Lee appeared certain to score his second try after a Newcastle scrum win, Panthers playmaker James Maloney forced the ball loose with a try-saving tackle.

"Their try just before half-time, the effort from their winger to get the ball back in, and we had a walker," he said.

"Then you get Eddy at 104 or 105 kilos and Jimmy Maloney coming up with a one-on-one strip, and Jimmy’s only a little bloke. That was us as a team, not any one person, but I just thought they beat us to the punch a couple of times in real key moments.

"Were they that much better than us? No, but they got some better attacking kicks in and gave their blokes some better shots at it – we probably weren't as good there – but there wasn't a huge amount in the game.

"I just thought there were a couple of times there where if we worked a touch harder, or if individuals worked a touch harder, we might be sitting here with a smile on our face."

Knights five-eighth Kalyn Ponga had a chance to level the scores at 10-all at half-time but missed a long-range penalty goal. It was his only miscue of the night, but a costly one in the wash-up.

The other play in which the Panthers were rewarded for their energy and enthusiasm occurred five minutes into the second half, when forward Isaah Yeo fought through attempted tackles by Watson, Danny Levi, Herman Ese'ese and Sione Mata’utia to score and extend Penrith’s lead to 16-8.

Yeo, who had been concussed against Parramatta last Sunday, was replaced in the third minute against Newcastle with another apparent head knock but returned in the 30th minute.

Panthers coach Ivan Cleary clarified that Yeo only needed stitches to close a cut near his eye and was not replaced for a head injury assessment (HIA).

"That was a shocking try, just after half-time when we were fresh as anything. Isaah Yeo gets knocked out twice and he’s got more energy to run through the middle," Brown lamented.

"We had lots of goal-line 'D' where we held them out really well, and we had lots and lots of good.

"But when you're playing these blokes that are good players, you've got to be good across the board but we weren't. We lost by two and we had those chances over the line and missed a goal kick just before half-time … so we weren’t terrible.

"We just weren't quite there, and when you're not quite there, you can't expect to do well enough at this level. They forced a bit of that issue with their good line speed, and their hunger and desire, so they forced the issue quite well.

"That’s probably the dog and the bone, I reckon, and they probably got the bone a little bit more."

Knights bench forward Mitch Barnett gave Newcastle fans hope when he charged over to score in the 73rd minute to cut the margin to two points after Ponga converted from in front, but they again squandered chances through poor handling in the final few minutes.