Guyra have landed in the winner's circle for the first time this season after accounting for Ex-Services in round three.
Servies won the toss and sent Guyra in to bat first with Shane Wolfenden and Brandon Landsborough beginning with a series of boundary shots.
After the opening pair, then number three Troy Martin, were dismissed, BJ Cameron and Matt Finlay put on a 64-run partnership before Cameron departed on 34.
Finlay went on to post 73, Guyra skipper Charlie White added 30 as his side managed a total of 259.
With the ball, a pair of returnees to Guyra's side were the standouts.
Tyson Burey snared the first wicket of Sreejan Tarafder for seven before Jake Ellis landed a trio of wickets, then Brandon Landsborough claimed one, to have Servies at 5-83.
Then Nathan Lane and Benji Marshall put on a 108-run partnership with the bat to keep Servies in the game.
Lane made 63 before Burey claimed his wicket and that slowed things up again.
Marshall finished on 68 not out, along with his skipper John Elliot on seven not out, but they ran out of time as their 45 overs were up.
Guyra captain Charlie White was happy overall with the victory, but was disappointed with their efforts in the field.
"Again, the fielding needed work," he said.
"It was not good at all.
"It is probably the main area we need to improve, especially coming up against Easts.
"If we make the errors we did on the weekend we are going to get a good score hit on us."