A deflected effort by former Cambridge United man Nathan Arnold condemned Posh to a first defeat in pre-season.Peterborough United were beaten 2-1 by a lively Grimsby Town side at Blundell Park as the Mariners made it eight wins in a row during their pre-season campaign.
It didn't take long for Dave Robertson's men to get themselves ahead and it was a stunning goal to break the deadlock, Kieran SADLIER unleashing a fierce drive from 25-yards which flew past goalkeeper Warrington.
Gabriel Zakuani produced a superb clearance off the line to deny Pittman's well-struck shot on 10 minutes as Town came close to a leveller.
Grimsby had the ball in the back of the net on 21 minutes as Gowling's header found Amond who fired home from close-range, but the offside flag cut short the celebrations.
The lively Pittman curled over from 25-yards on 26 minutes after the referee failed to spot a fairly blatant foul on Fox on the far side.
Vassell saw a left-foot shot from just outside the area deflect wide for a corner kick as Posh pressed for a second goal. Newell saw a curler beaten away by Warrington just after the half hour mark.
Dion-Curtis Henry made his first save on 43 minutes, denying Nathan Arnold with his legs after an intelligent lay-off from Pittman.
Former Posh goalkeeper James McKeown was introduced at the interval for the Mariners, replacing the experienced Warrington in between the sticks. Posh introduced Ricardo Almeida Santos for Zakuani.
The Mariners equalised on 50 minutes and it was a well-worked move from the hosts, Pittman again involved, but it was MARSHALL who finished it off, tucking the ball past Henry from close-range.
Just after the hour mark, Michael Bostwick replaced Jermaine Anderson in the centre of midfield while Grimsby made two changes to their starting line-up.
A mazy dribble from Newell saw him ghost past three players on 68 minutes, but his side-foot finish at the end of it went wide of the target. Posh made a double substitution with 20 minutes remaining - Jon Taylor and Marcus Maddison introduced.
Bostwick and Santos both saw goalbound efforts blocked as the game entered the final 15 minutes. Pittman saw a shot deflected wide for a corner kick after good work from Arnold down the left.
On 83 minutes, the Mariners got themselves a rather fortunate second goal as ARNOLD's speculative effort looped off a Posh defender and found the back of the net, leaving young goalkeeper Henry helpless.
Maddison fired over from distance as Posh tried to get themselves back in the contest.
Grimsby: Warrington (sub McKeown 46min), Tait, Pearson, Gowling (sub Sunter 70min), Disley, Amond (sub Mackreth 61min), Marshall (sub Monkhouse 61min), Clay, Pittman, Arnold, Nsiala. Unused subs: Clifton, Venney.
Posh: Henry, Adebayo-Rowling, Brisley, Zakuani (sub Santos 46min), Fox, Sadlier (sub Taylor 71min), J. Anderson, H. Anderson (sub Maddison 71min) , Newell, Vassell, Angol. Unused subs: Alnwick,, Oztumer, Payne, Ntlhe, Smith,
Taylor, Maddison, Washington, Gormley.
Half-time: Grimsby Town 0-1 Peterborough United
Full-time: Grimsby 2-1 Peterborough United
Attendance: 1,389 (42 Posh fans)