The Air Force overcame windy conditions at RAF Halton to seal a 20-5 victory in their first fixture of the calendar year.
After two solid days of training, it was the military side who took the first opportunity of the game. It was early in the match when Alex Barnes took advantage of a defensive mistake to score the first try.
Throughout the first half, the RAF’s performance was inconsistent, conceding several penalties.
However, they defended them solidly to keep the opposition out, while on the counter-attack they looked ruthless.
Cokayne, who has been announced as part of England’s Six Nations squad, played a part in the second try of the game. She played a pass to Kate Edwards to ran at the Police defence and laid it on a plate for Danniker Willmore to get over the line.
There was a time for a third RAF try before half-time. Emma Tadman shrugged off some weak Police tackles and fed the ball to Ruth Harper who gave the Air Force a 15-0 lead at the interval.
The second half continued to go the way of the RAF.
They had more of the ball and their two international talents were starting to be more and more involved. The fourth try came when Cokayne found a clever kick forward towards Tadman. A lucky bounce meant the ball fell back to the RAF attacker who went over for the try.
It was not to be a perfect day for the RAF though as the Police pulled a try back in the closing stages. Hanna Sherlock took the points, but the RAF strolled to a comfortable victory.
The win was impressive for the two internationals, who sung the team’s praises after the game.
“We had to show today what the first team is made of,” said Williams. “We have a lot of development girls who stepped in again today so it’s good this early on in the season for new girls to get time in an RAF shirt.
“The score is just a bonus for us.
"It was about performance. It was about putting down our structures early on and getting the girls to know how we want to play.”
For Cokayne, getting to play for the RAF this early into a year is a rare gift.
She said: “I think it’s a very rare occasion that both me and Sian have been available very early on. I think it’s something that we have wanted to do for a while now because normally we just get to play in the Inter Services games.
"You don’t get to bond with the girls and learn all the patterns for the way we want to play. If we can start blooding all these new players, we can be the old heads that can just talk and put them in the right place as they do all the work."
Cokayne will come up against her RAF team-mate Williams in the Six Nations as Wales host England on 24 February.