When the Warriors raced to a 28-6 half-time lead at Pepper Stadium on Saturday, the Panthers were booed off the field by their own fans.
Just 40 minutes later they had created history and saved their season.
It was one of those days.
The Panthers and Warriors set the season record for points in a game (64). The scoring frenzy lasted the whole 80 minutes. On a crazy and wildly entertaining Saturday night the Titans upset the Storm 38-36, combining for 74 points to kick-off a thrilling double-header in Brisbane.
By the time the Roosters had racked up 48 points against a listless Eels outfit on Sunday afternoon, Round 10 had become the highest-scoring round of NRL (400 points) since Round 25, 2015 (408).
It was Penrith's second biggest comeback in the club's history and the eighth biggest comeback the game has ever seen. It was also the biggest lead the Warriors have ever given up.
So what went so wrong for the Warriors and so right for the Panthers?
The Warriors scored five tries to one in the first half, despite having only 44 per cent of the ball. Their average play-the-ball speed was more than half a second slower than their opponents and they had made 15 ineffective tackles to seven. The Panthers were left to rue 16 missed tackles in the first half.
The Warriors took full advantage of a 12-man Penrith outfight - after Waqa Blake had conceded the most blatant of professional fouls in the 11th minute to be sent to the sin bin - racing in two tries and then seemingly putting the game to bed on the stoke of half-time with a length-of-the-field intercept.
While they racked up a big first half lead, the Warriors had only managed an extra five play-the-balls (15-10) inside the Panthers' 20-metre zone at the break.
Still, a 22-point lead should have been more than enough for a Warriors team looking to make it three wins on the trot with a place in the top eight on the line.
But then the siren sounded for half-time and the game completely changed.
In the next 40 minutes the Panthers ran for an incredible 720 more metres (1,145 to 425) than their shell-shocked opposition. They completed 23/24 sets at 96 per cent, forcing the Warriors to make 196 tackles in the second half, including 25 missed tackles (below).