The U's suffered their first league defeat of the season at Tranmere, going down 4-0 to Ronnie Moore's side.
An entertaining first half saw both sides looking to get forward at every opportunity and it was the home side who opened the scoring, Cassidy heading home on forty minutes.
The home side then ran away with things in the second period, with Cassidy completing a hat trick and Bakayogo scoring Rovers' other goal.
Boss John Ward made two changes to his starting line-up, with Karl Duguid and Andy Bond coming in the face Tranmere.
Ian Henderson and John-Joe O’Toole were the two missing out, as Ward made his first changes to his starting eleven in the league.
Tranmere boss Ronnie Moore also made two changes to his line up, with Bell-Baggie and Golobart replacing Taylor and Thompson.
The U’s began the game with a change to the formation as well as the personnel, with Sears moving up closer to Morrison centrally and Duguid and Wordsworth providing the width.
Both sides looked to attack from the start, with Akpo-Akpro shooting over on two minutes before play immediately switched to the other end.
First, Freddie Sears had a shot blocked on the edge of the area, before Andy Bond’s follow up shot went wide.
Seconds later, the U’s regained possession and Michael Rose’s cross was headed wide by Anthony Wordsworth.
The frenetic start wasn’t over yet, as Magnus Okuonghae had to slide full length to toe the ball away from Akpo-Akpro before the Tranmere striker could pull the trigger.
As the play settled down, the U’s looked comfortable in possession and were patient as they worked their way into the Tranmere half on occasions. The home side kept their shape though and the U’s couldn’t find a way through in the first fifteen minutes.
On that fifteen minute mark, the referee produced the first yellow card of the afternoon, booking Okuonghae for a pull on Cassidy.
There was a chance at each end as the clock showed twenty minutes, with Wordsworth denied by the keeper after a one-two with Morrison and Akpo-Akpro heading over from a wide free kick.
Tranmere then had two more efforts well off target, but Mark Cousins was still to make a meaningful save in the visitors’ goal.
The U’s were looking bright with the ball at their feet and in the twenty sixth minute, a surging run down the left from Sears resulted in a home defender having to be very quick to beat Morrison to the near post cross.
Sears was the provider again a few minutes later, as his cross eventually found Marcus Bean, whose volley was tipped over by Fon Williams.
With ten minutes to go before half time, Tranmere came close to opening the scoring, but Cassidy’s header came back off the upright.
The U’s broke immediately but Bond’s run wasn’t matched by the finish and Fon Williams collected comfortably.
On forty minutes, the home side broke the deadlock, profiting as the U's lost possession on the halfway line.
The ball found Robinson on the left and at the second attempt, he crossed to the near post for Cassidy to head home.
The U’s responded quickly though, as Sears whipped in a cross from the left that Fon Williams fumbled in front of Morrison before a defender intervened.
And it was the visitors who had the final effort of the half, with Wordsworth putting another free kick over the crossbar.
The second half started with Tranmere on the front, Rose having to deny Bell-Baggie with a sliding challenge.
Tranmere weren’t to be denied a second goal though, with Cassidy latching onto a through ball on forty nine minutes and calmly clipping the shot past Cousins.
U’s dangerman Sears had a sight of goal on fifty three minutes but the shot from Wilson’s cross lacked power and Fon Williams was able to save.
Bakayogo’s effort didn’t lack anything four minutes later, as a move down Tranmere’s left resulted in the left back’s shot beating Cousins to give the home side a 3-0 lead.
And it was nearly four a minute later, as Akpo-Akpro hit the post after another foray down the left flank.
It was all Tranmere as the game went by the hour mark and Ward introduced Henderson and Massey to try and turn the tide.
They had to watch though as the home side continued to put the U’s under pressure and Robinson shot narrowly wide from a tight angle.
Henderson did have the next effort on target at the other end, when his snapshot forced a smart save at the near post from Fon Williams.
Cassidy had scored the first two Tranmere goals and he completed his hat trick on seventy six minutes. A low cross came in from the left and Cassidy slid in to get to the ball first and put it into the bottom corner to make it 4-0.
Unsurprisingly, Tranmere took their foot off the gas for the final part of the game and the U’s couldn’t get any grip offensively, failing to test Fon Williams further.
It was a disappointing end to the afternoon on the Wirral, especially after the promise of better things in the opening period of the game.