Jack Cornish was the four-goal hero as Cosham moved into second place in division one after defeating a Ventora side still seeking their first point of the season.
Both teams took time to adjust to the tricky conditions, with Cosham’s Rob Fenwick close to taking advantage of a slip in the Ventora box but he couldn’t get any power in his shot.
After Cliff Little had blasted a shot just over the Ventora bar, Paul Johnson had Ventora’s first effort on goal but the ball hooked well wide.
Cosham went close to taking the lead on the half-hour mark, Fenwick’s incisive pass put Danny Jafkins in on goal. However his shot from an acute angle clipped the far post and went behind.
Goalmouth action was at a premium but Ventora defender Mark Cammerer did get his head to a Steve Horsley corner only for his effort to be hacked away by a defender.
As the half drew to a close, Ventora debutant Gareth Griffiths was denied the opener by a great last-ditch tackle from Cosham defender Alex Hobbs.
Little fired an effort into the side-netting off the fingertips of keeper Kieron Brennan and Cosham were ahead soon after.
Jafkins delivered a cross to the far post, Marty Tyrrell’s looping header was saved by Brennan but Cornish was able to force in the loose ball.
Cornish was close the doubling the lead two minutes later but Brennan managed to scramble his effort away, with Cosham claiming the ball had crossed the line.
It was 2-0 midway through the second half, though. Ventora conceded a free-kick on the left and Cornish rose at the far post to nod in from Tyrrell’s delivery.
Cornish then completed his hat-trick from the penalty spot. Brennan felled Craig Hicks and, after the Ventora keeper had been booked, Cornish confidently converted from 12 yards.
Tyrrell and Cornish combined soon after for goal number four. The former crossed low from the left and Cosham number seven Cornish flicked the ball inside the far post.
There was still time for Paul Johnson to slide in a late consolation for Ventora.
Portsmouth Saturday League division one
COSHAM PARK RANGERS 4 (Cornish 4)
AFC VENTORA 1 (Johnson)