As far as massive upsets go, this was right up there.
Leading into the match, it had been a matter of debate just how many points the Cowboys would rack up against a side sitting second-last on the table and on a five-match losing streak.
By the end of it, fans at Dairy Farmers Stadium were wondering what had happened, considering the relative form of the two sides.
But the result was rarely in doubt. In fact, the Cowboys were lucky to be trailing only 12-0 at the break and had fullback Matt Bowen to thank for keeping the deficit manageable.
Bowen, who has been outstanding on attack in 2007, showed he is also a more than handy defender, as he prevented two Penrith tries.
But he could do little to stop Frank Pritchard storming over in the 32nd minute and he watched in despair as Panthers front-rower Joel Clinton impressively gathered a kick ahead to score three minutes later.
The Cowboys enjoyed a wealth of possession in the second spell and it seemed only a matter of time before they got on the scoreboard. But the Panthers defence remained resolute and they even extended the lead with a crucial try to prop Brendon Worth.
Brett Anderson gave the Cowboys a glimmer of hope but it was short-lived, with Luke Lewis crossing in the 67th minute to put the game out of the home side's reach.
In last night's other game, the Raiders downed the Rabbitohs 16-10.
Cowboys 12 (B. Anderson, S. Bolton tries, J. Thurston 2 gls) Panthers 22 (F. Pritchard, J. Clinton, B. Worth, L. Lewis tries, M. Gordon 3 gls). HT: 0-12.
Broncos five-eighth Darren Lockyer is confident he will recover in time to lead Queensland in the opening State of Origin match on May 23.
The Maroons skipper injured his troublesome ankle in the Broncos' 16-8 loss to the Sharks on Friday night and immediately left the field to seek treatment.
But Broncos coach Wayne Bennett was optimistic he would be fit in time.
Both sides will be named on Tuesday.