Millwall 4-1 Barnsley

Aiden O'Brien struck twice as Millwall reached the FA Cup fourth round by coming from behind to beat 10-man Barnsley.

The hosts trailed when Brad Potts struck early on but O'Brien drilled in an equaliser and teed up Ben Thompson for the second shortly after the break.

Joe Williams was dismissed for a vicious tackle on Jed Wallace and O'Brien curled home four minutes later.

Fred Onyedinma added a fourth, lifting a finish over Tykes keeper Adam Davies.

Millwall - quarter-finalists last season - are four places and four points better off than Barnsley in the Championship table and the scoreline perhaps flatters them in a game where they had the same number of shots and 49% possession.

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But Barnsley capitulated in the 21 minutes from O'Brien's equaliser to his second on 56 minutes - the game's stand-out strike after he showed good control before a composed finish for his fourth goal of the season.

Williams' red card was key as Barnsley faltered. They will rue missing chances for Tom Bradshaw and Dimitri Cavare when 1-0 up and now have just one win in 12 matches.

Millwall boss Neil Harris:

"I was delighted for Aiden. He's been a goal threat in every game he's played, he's been close and denied from goal-line clearances and the woodwork, but to get a couple today will do his confidence a world of good.

"I thought the 20 minutes before half time and 20 minutes after half time were the best we've been this year."

Barnsley manager Paul Heckingbottom:

"Although it was 1-1 at half time I felt we'd missed an opportunity and I saw signs that we weren't really defending properly.

"The second goal was a clear indication of that and then the sending off obviously puts us on the back foot.

"I'm really disappointed. However, the only saving grace is that there's not three points lost on this game today."