OXFORD United dug deep to earn a hard-earned draw in Essex, but they could have left Roots Hall with more than a point.

Few would have sniffed at the result on a rain-soaked day where the U’s needed to ignite their Sky Bet League One campaign.

Although they could have claimed victory in stoppage-time when John Mousinho saw his header saved by Mark Oxley, a much-improved and battling performance ended a run of four straight defeats.

But evidence of their struggles rang true at the final whistle when Plymouth Argyle’s 1-0 victory over AFC Wimbledon saw the U’s drop to the foot of the table.

United made four changes from the mid-week defeat to Luton Town and, after switching to 4-4-2 on Tuesday, Karl Robinson experimented with another formation in the form of 4-3-3 for the first time this season.

Mousinho returned to skipper the side in front of the defence, with Josh Ruffels starting at left back, James Henry forming part of the midfield three, and Jamie Mackie spearheading the attack.

United headed to Essex in desperate need of a victory, but Roots Hall has not been a happy hunting ground in recent years, with their last league victory coming back in December 2003.

The visitors received bad news in the warm-up when Charlie Raglan rolled his ankle, meaning the U’s would name only six substitutes.

United found themselves on the backfoot early on and goalkeeper Jonathan Mitchell was called into action on nine minutes when he beat away Tom Hopper’s shot from a narrow angle.

The visitors were soaking up pressure as Southend, riding high with confidence after three-straight wins, knocked the ball round with purpose on a slippery surface.

United’s first shot on goal arrived on 19 minutes, when Gavin Whyte collected Ricky Holmes’ crossfield pass and drilled a 20-yard shot wide of Oxley’s right-hand post.

But it proved to be only a breather from their defensive duties as Southend continued to dominate proceedings and only a vital tackle from Mousinho stopped Hopper racing on to Simon Cox’s beautifully weighted pass.

The latter then came closest to opening the scoring on 29 minutes and was unlucky not to do so.

Jason Demetriou’s pass found Cox in acres of space on the right-hand side of the area and the striker drilled a ferocious shot which cannoned back off the underside of the bar and off a post to safety.

United could breathe a sigh of relief as a half they found themselves on the backfoot for the most part petered out.

The U’s started the second half positively, Mousinho feeding Holmes on the left and his cross flashed dangerously across the six-yard box.

Robinson wanted his side to be aggressive on and off the ball and they were beginning to show it in abundance.

But they were still lacking in the final third, where Mackie worked tirelessly to put the home defence under pressure.

United looked the more likely to break the deadlock, with Holmes and Whyte causing problems, and the visitors carved out their best opportunity of the match on 71 minutes.

Mousinho collected an overhit Tony McMahon free-kick and his inswinging cross was glanced wide by an unmarked Mackie.

An even better chance fell United’s way seven minutes later, but McMahon’s whipped cross was headed wide by Holmes at the back post.

Individual errors have hindered the visitors in recent weeks and they were nearly caught out on 79 minutes, but Dru Yearwood fired wide from the edge of the area after Mousinho had been dispossessed.

Mackie was then involved in a collision with Moore, with home fans calling for the United striker to be sent off for an alleged elbow.

Fortunately for the visitors, he was only booked and as the game petered out, they carved out one final opportunity in stoppage time.

McMahon swung in a free-kick and Oxley did brilliantly to keep out a Mousinho header, before Southend scrambled clear after Josh Ruffels saw his follow-up shot blocked.

It was a big chance and a win would have been deserved, but they were forced to be satisfied with a point.

Southend Utd (5-3-2): Oxley, Demetriou, Turner, Moore, White (Kightly 37), Coker, Dieng, Yearwood, Mantom, Hopper (McCoulsky 73), Cox (Robinson 82).

Unused subs: Bishop, Bwomono, Klass, Hendrie.

Booked: Demetriou.

Oxford Utd (4-3-3): Mitchell, McMahon, Nelson, Dickie, Ruffels, Mousinho, Henry, Brannagan, Holmes, Whyte, Mackie (Obika 83).

Unused subs: Shearer, Smith, Garbutt, Hanson, Raglan, Long.

Booked: Mackie, Whyte.

Referee: Craig Hicks (Surrey).

Attendance: 6,234 (436 U’s fans)