Champions Spencer inflicted the first wound in the battle for the Prem with a convincing 13-5 victory over Hampstead.
The Earlsfied team stormed out of the blocks determined to prove a point and the deadly finishing of Rob Holmes underscored their title charge.
He blasted three goals in the first quarter as Spencer took the game by the teeth and never let go.
The Men in Black were 6-1 down at the end of a breathtaking Q1 display by the home team in the only top flight fixture played.
Holmes continued to find the target to finish with five goals as Spencer outscored their rivals in the final two quarters after a goal-less second Q.
Hampstead struggled to live with a top class performance that takes the holders back to the top of the Prem for the first time this season.
Rick Bone was at his shot-stopping best as Hampstead managed just two goals in the first three quarters before mounting a spirited comeback in the final quarter although they were still outscored 4-3.
Dom Sandy and Tom Stewart were influential in midfield and up front Freddie Evans grabbed a hat-trick while Holmes was defensive headache all afternoon.
Spencer now lead Hillcroft by two points and have a game in hand with Hampstead in 5th.
The teams will meet again in the Flags semi-final at the Westway on February 27 followed by the return league fixture on March 12.
“We've been aiming for consistency all season and have been training hard for that,” said Spencer co-captain Joe Darkins. “From the first whistle we came out of the blocks with intent to score and it was great to go into a five goal lead in the first quarter despite injury to top attacker Will Walker.
“The second quarter saw no goals but plenty of chances with both teams having opportunities. It was important we didn't concede to maintain our lead and resilience.
“Into the third and fourth quarter we outscored Hampstead in both to finish the game off. We were disappointed not to get more on the score sheet as we had the chances but our finishing let us down at times.
“In defence, we managed to contain a number of D1 players of high calibre. Stand out players were Rick Bone in goal, Rob Holmes with some impressive finishing and Dom Sandy and Tom Stewart in midfield.”
With both their 2nd and 3rd teams undefeated in the league, Darkins paid tribute to the club’s commitment to the game.
“It was a great team performance built through the club foundations we work on weekly during training from the juniors all the way through the senior squads,” he added.
Purley has the unenviable task of visiting a wounded Hampstead at the Westway this Saturday while Spencer entertain Cardiff.
Hillcroft travel to Reading in a bid to reignite their title campaign while the match of the day looks to be Blues at East Grinstead.
East Grinstead v Blues (12:00noon)
Hampstead v Purley (1:00pm)
Reading v Hillcroft
Spencer v Harlequins