Saracens will head into the second leg of their round two Parker Pen Challenge Cup clash against Colomiers in confident spirits after Sunday's convincing 16-6 victory.

Wayne Shelford's London side prevented their visitors from scoring a single point for the first 50 minutes.

And despite a tough trip to France next weekend they look firmly on course to qualify for next month's quarter-finals.

Saracens fullback Adryan Winnan eased the home side into a 6-0 lead with two early penalties though their advantage could have been greater if the 19-year-old had converted two other efforts.

French international Thomas Castaignede, playing for the first time for Saracens at fly half, then converted a 24th minute penalty to put the Watford outfit 9-0 up.

A converted try by Darragh O'Mahony gave Saracens a comfortable 16-point cushion before the break.

The Vicarage Road side, having dominated possession and territory for much of the first half, finally broke through Colomiers' defence and made the most of the sin binning of hooker Thibaut Algret for O'Mahony to touch down unchallenged.

Fly half David Skrela broke the deadlock for Colomiers after 51 minutes with a penalty and then added a second with 71 minutes gone.

Saracens, in contrast, lost the momentum and the home side in fact only had one decent chance of scoring during the second half and substitute Andy Goode missed that opportunity with a wayward penalty kick at goal.