Walsall crashed to their heaviest defeat of the season despite taking the lead as Southampton ran riot.

Matt Richards’ stunning 25 yard free kick put the Saddlers ahead after just three minutes, but the Saints roared back with first-half goals from Jason Puncheon and Lee Barnard’s double.

Rickie Lambert added a fourth after the break and Adam Lallana piled on the misery in the 89th minute.

Goalkeeper Clayton Ince was dropped after the mistake which gifted Yeovil their winner on Tuesday, as Rene Gilmartin returned for the first time since October.

Defender Rhys Weston made the bench following his hamstring injury, but Manny Smith missed out with a virus.

The game was barely underway when Richards stunned St Mary’s. Troy Deeney was bundled over 25 yards out and the left-back stepped up to curl a delightful strike into the top corner.

Immediately Lambert’s header was pushed wide by Gilmartin, before the goalkeeper saved well from Barnard.

It was a cut and thrust opening which continued unabated when the Saints levelled after eight minutes.

Lambert cushioned a header down to Puncheon, who was allowed time to set himself and bury an 18 yard effort off the post.

The hosts began to dominate and Barnard’s header was disallowed for offside, after Gilmartin pushed Dean Hammond’s effort onto the bar after 20 minutes.

But the striker wasn’t to be denied 12 minutes later when Lallana’s shot was blocked by Jamie Vincent and the former Southend man rammed home the rebound.

It was a deserved lead but the Saddlers almost hit back immediately, when Dan Harding stopped Clayton McDonald’s header on the line.

The near miss didn’t shock Southampton and they scored a third on 36 minutes, when Barnard was left woefully unmarked to fire past Gilmartin.

Southampton were rampant and Lambert was hunting more when his shot flashed inches wide just before the break.

Hammond could have added a fourth in first-half injury time, but his header was cleared off the line by Richards before Gilmartin saved the follow up.

The Saddlers would have been pleased to reach the dressing room and survived the opening 10 minutes of the second-half, before Richards hacked Hammond’s effort off the line.

But the Saints grabbed a fourth on 62 minutes, when Lambert outmuscled Darryl Westlake and fired in from an angle.

Alex Nicholls finally broke the Saints’ dominance when his drive was saved by the underworked Kelvin Davis in the home goal, while Lallana should have added a fifth but blazed over.

The midfielder finally grabbed his goal in the final minute, turning in Papa Waigo N’Diaye’s cross.