Sidney Crosby was on target as the Penguins saw off the Florida Panthers 3-1 for a third succussive win.
The Islanders, meanwhile, made it four victories on the bounce with a come-from-behind 3-1 success at home to the Tampa Bay Lightning.
Pittsburgh remain two points clear of the Islanders in the Eastern Conference's Metropolitan division, with 48 points from 32 games - one less than the New York franchise.
The Penguins made a blistering start to proceedings at the Consol Energy Center, with goals to Nick Spaling and Derrick Pouliot helping the hosts to a two-goal lead by the seven-minute mark.
Spaling opened the scoring less than two minutes into the first quarter, sending a wrist shot past Panthers goaltender Roberto Luongo, who finished with 31 saves.
Pouliot - on his NHL debut due to numerous injuries - doubled the lead five minutes later with a powerful shot that went into the top-right corner of the net.
The Panthers hit back less than a minute later through Vincent Trocheck, who scored a power-play goal as the visitors generated some momentum heading into the second period.
But after a goalless second term, Crosby - who has struggled with the mumps recently - put the game beyond doubt 7:01 into the third period.
Marc-Andre Fleury clocked up 45 saves for the triumphant Penguins.
The Islanders saved the best till last in New York, scoring all three goals in the final period to get the better of the Lightning.
Tampa Bay were seemingly on track for a narrow one-goal win on the road thanks to Brett Connolly, who broke the deadlock 9:16 into the third period for his sixth goal of the season.
But with less than four minutes remaining on the clock, John Tavares equalised via a high shot that left goaltender Andrei Vasilevskiy (47 saves) helpless.
And the Islanders took control from that point, Anders Lee putting the hosts' ahead 12 seconds later before Nikolai Kulemin scored an empty-net goal.
Elsewhere, the Toronto Maple Leafs crashed to back-to-back defeats after losing 7-4 to the Philadelphia Flyers.
The Washington Capitals shutout the New Jersey Devils for a 4-0 win, the Chicago Blackhawks were beaten 3-2 in a shoot-out against the Columbus Blue Jackets, while the New York Rangers downed the Carolina Hurricanes 3-2.
Reigning Stanley Cup champions the Los Angeles Kings defeated the Arizona Coyotes 4-2, the Montreal Canadiens saw off the Ottawa Senators 4-1 in an all-Canadian affair and the Colorado Avalanche crushed the Buffalo Sabres 5-1.
The Nashville Predators held on to trump the Minnesota Wild 6-5 in overtime, the Vancouver Canucks upstaged the Calgary Flames 3-2 and the San Jose Sharks emerged 3-2 victors in overtime against the St Louis Blues.