Belsize Park overcame the worst conditions they had experienced for some time to secure their 11th successive victory and move 17 points clear of their nearest pursuers in the promotion fight.

Torrential rain meant St Albans’ pitch was a mudbath in the second half, but Belsize were already well on their way to victory at the interval.

Ryan Forrester and Will Ville both scored tries, which were converted by Jeremy Burton, who also kicked two penalties to give the visitors a 20-0 lead before the hosts hit back with a late try in each half.

Second-placed Belsize remain one point behind leaders London Nigerian, who beat third-placed Finchley 15-10 and thereby increased the gap between the top two teams and the rest.

With five games left, Belsize are 17 points ahead of Finchley and comfortably on course for promotion, while their next game on March 5 comes away against basement boys Wasps, who have lost all of their 17 league games this campaign.

Belsize’s director of rugby Zach Webb said: “I’m just relieved that we kicked the two penalties in the first half to put the game beyond doubt before the conditions made it effectively unplayable in the second.

“We had a very honest effort from our pack, led a real man-of-the-match and captain’s performance from George Hazlett.

“Our backs were clinical when it mattered and we had minimal errors. We were focused on minimising risk; allowing territorial prowess and defensive pressure to let the opposition make mistakes in key parts of the pitch. We couldn’t have asked for much more, considering.”

Belsize scored the opening try after 10 minutes as outside centre Ryan Forrester ran an incisive line to cut through the opposition’s line untouched and sped 35 metres to score beside the posts, with full-back Burton adding the extras.

The pressure continued and, minutes later, St Albans were caught offside and Burton slotted the resulting penalty between the sticks from 30 metres.

Jamie Niven’s positional kicking was a key factor in the visitors’ victory and, when he tested the home side’s full-back with a high kick, Belsize’s chasers forced an error and scrum-half Richard Turner scooped the ball up and put blindside flanker Ville in under the posts.

Burton added the conversion again and then slotted over another penalty after an infringement at the ruck to put his side 20 points up.

St Albans hit back before the interval with a try in the corner from a lineout maul and, although both sides struggled to sow phases together and hold onto the ball as the conditions worsened after the break, they scored again shortly before the end.