Two goals in the first half condemn Posh to a 2-0 defeat as Wrexham take all three points back to Wales.
It was an afternoon of frustration for Peterborough United as Wrexham continued their excellent start to the new campaign with a 2-0 victory at the Weston Homes Stadium with a deflected strike from Jack Marriott and a header from a corner earning the visitors all three points.
Posh started the game well and looked the more likely to break the deadlock but chances were hard to come by until the 17th minute when superb work from Abraham Odoh down the left created an opportunity for Malik Mothersille, but he couldn't covert from close-range.
On 27 minutes, the visitors opened the scoring and it was inevitably MARRIOTT who was on the score-sheet as his strike took a deflection and found the back of the net.
On 39 minutes, the Red Dragons doubled their lead as a corner from the right was headed home from close-range by CLEWWORTH.
Jack Sparkes fired over the top four minutes before the break before the visitors came close to a third as O'Connor's free-kick cannoned back off the crossbar.
Joel Randall had a chance to reduce the arrears but fired wide of the target before Ollie Palmer became the first player to be cautioned. Sparkes was cautioned moments after the break for a shirt tug before his cross was headed wide by Kyprianou.
Wallin couldn't divert a deep Conn-Clarke free-kick on target before the former Altrincham man curled a shot inches past the post with his left-foot after a neat turn in the box.
Substitute Mullin cushioned a volley wide on 69 minutes as Wrexham caught Posh cold on the counter attack. Posh huffed and puffed but couldn't create another chance and the visitors departed home with all three points.
Posh: Steer, Curtis, Collins (sub Nevett 79min), Wallin, Mothersille (Sub Jones 67min), Odoh, Poku, Randall (sub Conn-Clarke 46min), Sparkes, Kyprianou, Fernandez. Unused subs: Bilokapic, Dornelly, O’Brien-Brady.
Wrexham: Okonkwo, Cleworth, O’Connell, O’Connor, Mclean, Cannon (sub Rathbone 60min), Palmer (sub Mullin 68min), Marriott (sub Fletcher 68min), Dobson, Barnett (sub Revan 82min), Lee. Unused subs: Burton, Faal, Scarr.
Half-time: Peterborough United 0-2 Wrexham
Full-time: Peterborough United 0-2 Wrexham
Attendance: 12,104 (1,579 Wrexham fans)
Referee: Carl Brook.