Ryan Tunnicliffe’s second-half goal was not enough as defensive lapses cost Millwall in their first Championship defeat this season away to Sheffield Wednesday at Hillsborough.

Barry Bannan struck the Owls into the lead when Tunnicliffe’s hashed clearance saw the midfielder lash the ball on the underside of the crossbar and in.

After George Saville was withdrawn at half-time amid injury fears, Tom Lees doubled the lead before the Lions got one back with under 20 minutes remaining.

Millwall, who won 2-1 against Derby County at the weekend, have now lost in the league away from home for only the second time since New Year’s Day in January.

Shaun Williams was not in the squad which went to Hillsborough as Tunnicliffe in the only change from their win over the Rams.

It took just over 15 minutes for the Wednesday to get in front as Bannan’s volley in off the crossbar following Adam Reach’s hastily cleared cross.

The Lions responded quickly to try and equalise, however, execution in the final third proved to be lacking for them.

Saville went down shortly before the break and continued on until half-time, before Jake Cooper met a Jed Wallace cross but his header bounced wide.

And 40 seconds into the restart after Saville was replaced by Harris with Conor McLaughlin, Wednesday captain Lees finished from close range for the second.

By the hour, all three of Millwall’s substitutes came on and the breakthrough came on 72 minutes when Tunnicliffe found the bottom-corner past Cameron Dawson.

Millwall were agonisingly close to equalising at the death through James Meredith and new signing Jiri Skalak but could not break Wednesday’s rearguard.