MANCHESTER, Sept 16 (Reuters) - Unhappy ⁠Manchester United fans witnessed something unseen at Old Trafford in ⁠half a century on Wednesday as their side lost 3-2 ‌at home to Brighton & Hove Albion in the third round of the League Cup after going two goals up.

The last time United lost at home after leading by ​two goals was in September 1976 when Tottenham ⁠Hotspur won by the same ⁠scoreline.

While Brighton progress to the last 16, defeat was another blow to ⁠a ‌Manchester United side who suffered acontroversial 1-0 loss to rivals Manchester City in the Premier League last weekend and are ⁠13th with one win from four games.

United conceded ​twice in four ‌second-half minutes after teenager Shea Lacey had put them ahead in ⁠the eighth ​minute and Mason Mount made it 2-0 two minutes later.

Charalampos Kostoulas pulled one back in first-half stoppage time before Pascal Gross equalised in the 65th ⁠and Maxim De Cuyper hit the winner in ​the 69th, with the home fans booing at the final whistle.

"We can't accept that as a group. I take responsibility for it. The performance ⁠towards the end of the second half, that's on me," manager Michael Carrick told Sky Sports television.

It was the third successive domestic cup loss for United after they went out in the second round of ​the League Cup on penalties at fourth-tier ⁠Grimsby Town last season and lost 2-1 at home in the third ​round of the FA Cup to Brighton ‌in January.

Last season was the first time ​since 1981-82 that United failed to win a round of either domestic cup competition.

(Reporting by Alan BaldwinEditing by Toby Davis)