Chelsea took full advantage of some appalling Oxford defending at the Manor Ground on Friday to run out comfortable winners of their pre-season friendly.

And, although the Premier League side fielded a strong starting line-up, the manner of the goals United conceded will be a big concern for boss Denis Smith.

Two mistakes inside the first 15 minutes put Gianluca Vialli's side firmly in control. And by the time Richard Knight dropped a clanger for No 4 after 33 minutes, the game was as good as over.

The defeat highlighted that United, although up against an awesome array of talent, still have a lot of work to do before the opening match of the season in two week's time.

With several United players virtually non-existent in the first half, Chelsea stamped their authority on the game from the first whistle and only stepped up a gear when they needed to.

They went ahead after just four minutes when Gianfranco Zola's corner was met by the unmarked Gustavo Poyet at the near post and his header gave Knight no chance.

Oxford had their backs to the wall and Anders Jacobsen denied Jimmy Floyd Hasselbaink with a last-ditch tackle.

But, moments later, a ball out of defence found Zola in acres of space down the Oxford left and, with no defender coming across to tackle him, the little Italian calmly fired past Knight from a tight angle.

It took Oxford 18 minutes to have their first shot of the game, Simon Weatherstone's effort going well wide from the edge of the box.

But the game was put beyond United when a Zola chip fed Hasselbaink and the 15m striker, although looking suspiciously offside, slotted home through Knight's legs.

And United's first half misery was complete when Knight uncharacteristically spilled Zola's shot for Hasselbaink to tap home his second.

Smith reverted to a three-man back line at the interval, bring on triallist Lee Jarman to partner Jacobsen and Ian McGuckin and his tactical change succeeded in closing the game up.

But Chelsea continued to push forward and shots from Poyet and Gabriele Ambrosetti made Knight work.

However, Ambrosetti didn't have to wait long to get on the scoresheet.

Jarman tried to cut out Mario Melchiot's pass and was unfortunate to see the ball fall nicely into the path of the incoming midfielder who hammered a vicious shot past Knight.

But Oxford did at least fight back and scored a consolation when a quick free kick from the stylish Dean Whitehead was met by the head of Jacobsen, whose header was well saved by Carlo Cudicini, but the keeper was powerless to stop the defender firing home the rebound.

Whitehead must have been one of the few plus points in an otherwise disappointing night for Smith, passing the ball with confidence when he came on.

But on the whole, it was a terrible night for the U's, who must learn from their mistakes if they are to put up a decent showing in Division 2 this season and quickly.