Police remained unbeaten at the top of the Becks League after defeating a Mariners team who walked off frustrated at conceding a string of second-half penalties.

Following a dreary first half, when most players seemed to be getting over three weeks of inactivity due to the World Rugby Classic, the second half was a tense, physical period, too often punctuated with infringements and the inevitable referee's whistle.

Indeed, being on the receiving end of a barrage of penalties in the second half increasingly annoyed Mariners players, some of whom approached referee Peter Borland, both during the game and after the final whistle.

While the majority of Mariners' infringements were incurred at ruck and maul, where Mariners still seem to have problems understanding the laws, several decisions made by Borland appeared trivial and spoiled the flow and quality of the game.

Referees are allowed to have off-days and Borland is a capable official who might chalk this one up to experience and come back stronger next week.

Mariners surely have the most aggressive defence in the league, time and again putting in huge tackles to stave off the Police onslaught.

The Blues had the better of early exchanges, resulting in a good try after five minutes for centre Greg Lunn after he cut back inside, catching the Mariners defence on the wrong foot. Alan Oliver converted to give Police an early 7-0 lead.

Police spent the next 20 minutes in the Mariners' 22 and several breaks by Gareth Davies and Dave Bird from the base of the scrum were thwarted by a superb back row defence of Simon van der Weg, Bill Zuill and Roger Marshman.

Mariners continued to live off scraps of loose possession, being outplayed in the scrums and lineout. Nevertheless, Mariners' scrum half Josh McGavern got his backs moving well with their meagre possession and Rob Morgan and the returning Danny McGavern looked dangerous on the burst.

Morgan also put in some crunching tackles to thwart any breaks made by his opposite number Shane Richmond.

Oliver rounded off the first half with two penalties to extend the Police lead to 13-0.

Police rarely moved the ball wide and continued to use the cut-back from centre to meet up with their dominating forwards. Continued infringements at ruck and maul annoyed Mariners into action and McGavern had a big influence in the first try by wing Simon Hurstenstein.

Police pulled 11 points ahead with another Oliver penalty 15 minutes from time, but five minutes later McGavern saw an opening in the Police defence and scored a blistering try to leave Mariners only six points behind at 16-10.

Constant pressure from Police was resisted by some great defensive tackling by Deveray Noel-Simmons and Kevin Smith, but Police rounded off their victory with a disputed try by Davies.

It was a disappointing result for Mariners, but this was an impressive, controlled performance from Police.

This weekend pitches Teachers against Mariners, Teachers having won their first encounter on October 2 by 30-12. Renegades entertain unbeaten Police, having lost 30-14 in their last clash.

Teachers should win by a bigger margin this time as they are now at full strength and Police should easily get past Renegades who are likely to have too many weaknesses in key positions.

Last Saturday's scheduled Teachers v Renegades First Division fixture was replaced with a friendly match against the visiting Harvard University, the Teachers/Renegades combined team winning 56-12.

In 2nd XV League action, Teachers came back from a 10-5 half-time deficit to win 27-10, with new prop Des Davies and Andrew Correia outstanding, while Mariners whitewashed a poor Renegades outfit 25-0.