Veteran scrum half Sean Long, appearing at home for the first time since announcing his end-of-season move to Hull, produced another masterclass to help lay the foundation for the emphatic victory before stepping aside to allow his likely successor, Kyle Eastmond, to finish the job off.

Despite conceding an early try to Brett Ferres, Saints hit a purple patch to score four tries in 15 minutes through Leon Pryce, Chris Dean, Keiron Cunningham and Jon Wilkin to gain a firm hold of the match.

After scoring Saints' fifth try and kicking a third goal 12 minutes into the second half, Long was withdrawn as a precaution after feeling a calf strain but there was no respite for the outclassed visitors.

Eastmond took over, scoring two tries and kicking four goals from as many attempts as Saints took the opportunity against their depleted opponents to boost their points difference.

"It's pleasing to get 50 points and score some real good tries," added Potter. "I thought we were maybe unlucky not to get a couple more."

The win stretched Saints' lead at the top to five points after Hull KR crashed to a 40-10 home defeat against Harlequins.