Colin Blackwell, Mika Zibanejad, Ryan Strome, Alexis Lafreniere, Kaapo Kakko and Pavel Buchnevich also scored for New York, which extended its point streak to four games (3-0-1). It was the first time in 11 years that eight Rangers scored in a game.
Igor Shesterkin made 42 saves in his fourth consecutive start.
"We've got a great group of guys in there,'' Fox said. "We have a pretty young team and a hungry team. We only have so many games left and we're trying to make a push for the playoffs. Everyone in there is hungry. This is the fun part of the year. Every point matters.''
Jared McCann, Mike Matheson, Jake Guentzel and Brian Dumoulin scored for Pittsburgh, which lost for the second time in seven games. Tristan Jarry allowed four goals on eleven shots before being replaced by Casey DeSmith. Defenceman Kris Letang chipped in with two assists.
The Rangers stormed out of the gates and led 3-0 midway through the first period.
Blackwell opened the scoring with his 10th of the season after his pass attempt deflected off a Penguins defender and surprised Jarry at 1:35. Blackwell became the sixth New York player to score 10 or more goals this season.
Zibanejad doubled the Rangers' advantage at 7:28. He intercepted a pass in the defensive zone and then buried a rebound.
"It just looks like we are kind of lost,'' McCann said. "We are giving up chances we are not normally used to giving up. We are letting our goalies down right now and giving teams back-door tap-ins and shots from high-grade areas. We need to tighten it up.''
Panarin's snipe from the left faceoff circle increased the Rangers' edge to three at 9:58. Fox assisted and became the first Rangers defenceman to record 30 or more assists in each of his first two NHL seasons. The 23-year-old also extended his point streak to 11 games.
Strome capped off New York's four-goal first period with a power-play goal in the final minute. Panarin picked up the primary assist and recorded a three-point game for the sixth time this season.
"It was something we talked about, not backing off and stopping,'' Zibanejad said. "It's a good team we're playing against. That was a big goal, especially that late in the first and to be able to go into the second with a three-goal lead. The power play was clicking tonight from both units so that was huge.''
McCann's blast from the left point pulled the Penguins within two goals at 10:38 of the first. Letang and Sidney Crosby assisted on the power-play goal.
Pittsburgh outshot New York 18-11 in the period despite trailing 4-1 at the end of 20 minutes.
Lafreniere, the first overall selection of last year's draft, netted his sixth of the season at 12:20 of the second.
"I thought that goal they scored in the second was big,'' Rangers coach David Quinn said of Lafreniere, Kakko and Filip Chytil. "I thought they did a really good job of getting above the puck and I thought they made smart decisions. They were patient offensively, which we didn't have a lot of tonight. It was good to see them get rewarded going about it that way. Those guys are starting to play well and it was good to see them get rewarded.''
Matheson registered his fourth of the season 16 seconds later. The defenceman fired a shot past the glove of Shesterkin from the left faceoff circle.
Kakko deflected Trouba's shot at 6:10 of the third period to give the Rangers a 6-2 lead. New York converted all three power-play opportunities.
Guentzel hammered a one-time blast to cut the Penguins' deficit to three goals at 8:04 of the third period.
Fox and Buchnevich scored within 19 seconds of each other midway through the third period to put the game out of reach. Zibanejad forced a turnover and found Fox all alone in the slot for a short-handed goal. Buchnevich then buried a cross-ice feed from Chytil.
"We got to find a way to get back to some of the details that are necessary to give ourselves the best chance to win,'' Penguins coach Mike Sullivan said. "The quality of chances we gave up are not conducive to winning games consistently.''
Dumoulin scored his first of the season at 18:36 of the third.
The last time eight Rangers scored in a game was Jan. 19, 2010, against the Tampa Bay Lightning. It was the third time this season the Rangers scored eight or more goals.
Fox is the second Rangers player and first defenceman to tally a point on 11 consecutive power-play goals scored by the team since the statistic was tracked in 1933-34. The only other player was Red Sullivan in the 1958-59 season. The streak was snapped when Kakko scored on the man advantage in the third period.
The Penguins have allowed 15 goals over their last two games.
The teams meet again on Thursday night.