Having snapped a three-game losing streak by spoiling Leeds Chiefs' opening night party with a 4-1 win at Elland Road at the end of the last month, Ben Morgan's team have gone from strength to strength, following up Saturday night's 5-3 win at Raiders with Sunday's impressive showing on the East Coast.
It leaves the Steeldogs in sixth place but now within two points of Hull in fourth and fifth-placed Basingstoke. With 10 games remaining, the South Yorkshire club are within touching distance of third-placed Peterborough Phantoms, but it will require a herculean effort to overturn the seven-point deficit on the Cambridgeshire outfit.
In Hull, the visitors raced into a 3-0 lead inside 18 minutes, Cam Brownley, Alex Graham and Nathan Salem all getting on the board before Lee Haywood replied for the Pirates at 18.38. The three-goal cushion was quickly restored, however, when James Spurr added to his previous night's double at Raiders.
Sheffield piled on the agony for Hull when they got themselves 6-1 ahead through early, second period strikes from Craig Elliott and Jan Danecek, which led to Ash Smith being replaced in the Pirates net by Steve Hudson.
Bobby Chamberlain and Ryan Johnson then went toe-to-toe before Lewis Bell and Sam Towner also dropped the gloves as the game descended into a stop-start affair.
But any momentum Hull were hoping for failed to convert into goals, the Steeldogs going even further ahead at 33.07 through a second Brownley strike.
Player-coach Jason Hewitt pulled one back for his team before the second period was done and after two goals within the first two minutes of the third from Lee Bonner and Chamberlain, there was brief hopes of a revival for the home side.
But the damage had already been done, Vladimir Luka's power play strike in the 46th minute ensuring there would be no comeback, with Salem doubling his tally inside the final two minutes, taking his goal tally for the weekend to four after scoring twice at Raiders 24 hours earlier. Nathan Ripley was the other scorer for the visitors in Romford in an impressive road win.
Leeds Chiefs suffered a setback in their bid to take the eighth and final playoff spot, losing twice to Milton Keynes Lightning.
On Saturday, Sam Zajac's side got themselves into a 3-1 first period lead through strikes from Lewis Houston, Adam Barnes and Ethan Hehir, before Tomas Kana's second of the night made it a one-goal game at 17.45.
A goalless second followed before two goals in the space of 35 seconds did for the Chiefs, Tom Carlon's strike at 43.24 being quickly followed by James Griffin's effort which proved to be the game-winner.
On Sunday, the teams went in level after Houston's ninth-minute strike cancelled out Rio Grinell Parke's opener. But, as with the previous evening, two quick goals did for the Chiefs, Cale Tanaka's tap-in at 24.03 being followed 80 seconds later by a Taylor Dickin strike.
The Chiefs came close to closing the deficit in the third, Houston and Caly Robertson going closest, but the game was clinched with just under five minutes remaining when Liam Stewart cut in from the right-wing to fire past Sam Gospel.
It leaves the Chiefs 11 points adrift of the eighth and final playoff spot, which is now occupied by Bracknell Bees, who leapfrogged Raiders after a weekend double over leaders Telford Tigers.
"We do still feel like we’ve got time (to make the playoffs)," said Chiefs' player-coach Sam Zajac. "We’re going to battle all the way to the end. Don’t get me wrong, it is a mountain to climb in order to make it but it is only going to happen through hard work."
Tom Watkins's Telford side now have only a two-point lead over second-placed Swindon Wildcats after they edged out Basingstoke Bison in a 15-goal thriller in Wiltshire, the win making it a double over their Hampshire rivals after their 5-3 win on the road the previous evening.