Staal scored into an empty net at 18:02 for a 5-3 lead.
Ryan O'Reilly made it 5-4 with 42 seconds remaining to make it 5-4, but Martinook completed the hat trick with an empty-net goal with nine seconds left for the 6-4 final.
"It seems like any time we lose a game, it's usually 5-10 minutes where we give up a few chances that ultimately lead to goals, and that's what we've got to clean up," Krug said. "It's up to us to learn from those mistakes sooner than later. Otherwise, we're going to keep falling behind. We've got to make an adjustment there."
NOTES: Martinook's only other NHL hat trick came with the Arizona Coyotes on Nov. 23, 2018 in a 4-1 win against the Florida Panthers. ... Carolina has just one regulation loss in the past nine games (4-1-4). ... Jarvis has four points (two goals, two assists) in a four-game point streak. ... Buchnevich has 12 points (six goals, six assists) over the past eight games. ... Blues forward Jordan Kyrou had an assist to give him 14 points (five goals, nine assists) in the past 10 games.