The former Peterborough United player driving Derby County's promotion push, a mixed set of results for ex-Posh players on debuts and a club captain now in Saudi Arabia

Mo Eisa celebrates a goal for MK Dons (Photo by Pete Norton/Getty Images).

Mendez-Laing, who scored the 100th Posh League One goal of the 2010-11 season, was on target for the eighth time this season to seal a 1-0 win for the Rams at ailing Charlton Athletic.

That was enough to lift Derby from fourth to second, although Bolton and Posh have a chance to overtake them on Tuesday. Charlton are expected to confirm former Luton Town boss Nathan Jones as their manager in the next 48 hours.

Ex-Posh midfielder Ryan Broom was also on target as Fleetwood Town won for the first time since November to move off the bottom of the table. The Cod Army beat Port Vale 3-0.

Nathanial Mendez-Laing. Photo by Michael Regan/Getty Images.

Mo Eisa, a Posh record signing, could face his old club on Tuesday. made his debut as a substitute in Exeter’s 1-0 home reverse at the hands of Bristol Rovers,

In League Two there were goals for Matty Stevens (Forest Green) and Harry Anderson (Colchester) in a 3-3 draw, but Jack Marriott only came on for the final 10 minutes of Wrexham’s 3-1 defeat at Salford.

Peter KIoso started for Rotherham United in their 2-0 Championship defeat at home to in-form Southampton.

On-loan Posh player Kabongo Tshimanga made his debut from kick off for Boreham Wood in their 1-0 National League win at Woking.

Former Posh skipper Dean Holden has become Steve Gerrard’s assistant at Saudi Arabian club Al-Ettifaq.