Peterborough United were tested by a spirited Crewe Alexandra side at London Road, but overcame the challenges with an attacking display that produced four fine goals including a first for the club for Conor Washington.
The home side made a bright start and created a number of half chances in the opening exchanges, the best falling to skipper Tommy Rowe, but he couldn't keep his left-foot drive from the edge of the area on target.
Cameron Park was denied by Bobby Olejnik on 12 minutes as the visitors created their first effort on goal. On the quarter hour mark, Crewe took the lead and you have give tremendous credit to the goalscorer Chuks ANEKE who curled a superb effort into the top corner past the despairing dive of goalkeeper Olejnik.
The lead didn't last long as within two minutes, Posh were level. Washington was bundled over in the box by Harry Davies and ASSOMBALONGA coolly slotted home the spot kick.
Washington's pace and power was causing problems and he picked out Ajose after a good run, but the former Manchester United striker saw his low effort gathered comfortably by Garratt.
Bostwick, Swanson, Nugent and Washington all saw shots blocked in a short space of time while Brisley saw a header cleared off the line as Posh pressed.
Assombalonga diverted an Ajose shot towards goal moments later, but the outside of the post came to the rescue of the Railwaymen.
On the stroke of half-time, Posh got themselves in front as a swift counter-attack, which began from a clever pass from McCann to AJOSE, was ended as Swanson picked out the former Manchester United man who calmly finished past Garratt.
Pogba fired over after beating the offside trap before the interval as Crewe threatened an equaliser. The Railwaymen made a change at the break with Byron Moore replacing Billy Waters.
Assombalonga was denied on the goal-line before Bostwick saw his shot from the edge of the area routinely saved by Garratt.
On 58 minutes, Crewe got themselves level and once again it was ANEKE with the goal, more simple in it's execution than the first, rolling Nugent in the box, using his power to get into the shooting position and he calmly slotted the ball past Olejnik with his left-foot.
Pogba was immediately denied by Olejnik at his near post after finding space in the channel as wobbled. On the hour mark, Posh were back in front as Washington fed SWANSON and he fired low past Garratt and into the back of the net.
Assombalonga was somehow denied by Garratt and then Washington fired the rebound at the heel of his team-mate as Posh sensed a fourth goal was in the offing.
On 71 minutes, Ellis glanced a header from a free-kick wide of the target as Olejnik had ventured into No Man's Land.
Posh made it 4-2 on 87 minutes and it was the first goal for Conor WASHINGTON who fired home a superb half volley past the despairing dive of goalkeeper Garratt.
Aneke headed over in stoppage time while McCann saw a volley from 30-yards claimed by Garratt.
Final Score: Posh 4-2 Crewe Alexandra
Posh: Olejnik, Brisley, Bostwick, Swanson, McCann, Rowe, Ajose, Nugent, Washington, Little, Assombalonga. Unused subs: Day, Alcock, Baldwin, Payne, Anderson, Newell, McQuoid.
Crewe: Garratt, Tootle, Davis, Ellis, Pogba, Guthrie, Evans (sub Oliver 86min), Aneke, Waters (sub Moore 46min), Park (sub Ipeazu 72min), Grant. Unused subs: Phillips, Mellor, Dugdale, Nolan.
Attendance: 5,109 (214 Crewe fans)