Gareth Ainsworth could not understand why his Wycombe side had a goal disallowed at a crucial time before falling to defeat against Millwall.

Not long after Jed Wallace's penalty had cancelled out Scott Kashket's bizarre opener – Wycombe's first goal in the Sky Bet Championship – Joe Jacobson's corner drifted all the way in, only for the strike to be ruled out.

It appeared to be for a foul on Lions goalkeeper Bartosz Bialkowski, even though there was very little contact, and the visitors went on to make the most of their good fortune as Ryan Leonard's winner made it 2-1 to Millwall.

Ainsworth, whose team remain without a point, said: "Please tell me what is wrong with that because the referee has given a foul.

"There's absolutely nothing and I really hope people look at the replay and try and find out what the referee has given because to me that's a perfect goal.

"The fourth official has said there was a foul on the goalkeeper and, for the life of me – and I'm trying to look with non-rose-tinted glasses – I cannot see any foul at all.

"Joe Jacobson has been known to score direct from corners, but it's just not going our way at the moment.

"Battling-wise and showing heart and desire, I'm never going to criticise this lot. They've given me everything.

"We've made another mistake on a goal, which is really tough to take, but we've got a good squad, I'm really proud of the boys but as long as there's breath in me I'll be positive."

If there was one positive for Ainsworth, it was the return off the bench of striker Adebayo Akinfenwa from a knee injury.

Ainsworth said: "He's not fully fit by any means, but there were two big moments for me today: Akinfenwa coming on and Anis Mehmeti, a young Albanian who was released from Norwich, making his league debut."

Wycombe's first league goal of the season came when Kashket punished a dithering Bialkowski after nine minutes, as the hosts went into half-time ahead.

Wallace equalised from the spot three minutes into the second half before Millwall completed the turnaround in the 63rd minute through a terrific half-volley from Leonard.

Boss Gary Rowett was pleased to see the Lions recover well from a slow start, saying: "The first half was so frustrating, we got dragged into a game that suits Wycombe.

"That's why they got promoted – they're a side that haven't got the budget in this division, so they fight for everything and they will get results.

"Half-time was really about, 'are we going to show some quality or are we going to do what we've done all half, which was not play with composure?'.

"Our second half performance deserved to win the game.

"You don't need to say too much to Bart. As a goalkeeper you know you shouldn't have got caught on the ball.

"I would say that last season Bart probably won five or six games single-handedly.

"When you choose to put those gloves on that's the way it is. He has plenty of credit in the bank. But I don't want him doing that too much!

"Anyone that sees us play would never question our character. We're working hard to have a team who has much better balance. Our character is nearly always good."