Ali Carter reckons ‘brutal’ middle pockets were the reason for his gutting first round World Championship downfall.

The Colchester potter went down to a heart-thumping 10-9 defeat against world No.14 Jack Lisowski after letting an 8-6 lead slip at the Crucible.

The ‘Captain’, ranked nine places below his free-flowing opponent, missed a series of gilt-edged opportunities to slump to just his second first round defeat in Sheffield since 2006.

Carter was a two-time World Championship finalist in 2008 and 2012 and admits an inability to take his chances on the hallowed Crucible baize cost him dear.

The 41-year-old said: “The middle pockets are brutal – it’s disappointing.

“It’s just one of those things – I’ve had a red lip out of the middle pocket to go in on 50-odd, looking like 9-6 in front, and he’s cleared up from nowhere.

“That red’s gone round the lip twice and stayed out, and that was the turning point in the game.

“He’s entitled to leave me perfect when he’s missed his safety, I’ve got a tricky red in the middle, I’m closer on the cushion than I want to be on the blue digging down – and I’ve missed it.

“But he’s potted a great long red and made a good break.”

Carter has endured a turbulent season on the behind closed doors circuit but shown major signs of improvement in recent weeks.

The four-time ranking event winner reached the quarter-finals of the Welsh Open in February and was a defeated finalist at the inaugural Pro Series in Milton Keynes last month.

Carter qualified for the Crucible after beating Alexander Ursenbacher 10-4 and made breaks of 89, 61, 60 and 59 in the first session against Lisowski.

But he was unable to pull away as visits of 77 and 52 from the flamboyant left-hander soon levelled the scores at eight frames apiece.

Carter pinched the 17th frame to place him one away from victory but Lisowski, a six-time ranking event runner up, struck gutsy visits of 82 and 60 to edge over the line and book a last 16 date with world No.3 Neil Robertson.

It’s back to the drawing board for Carter but the Essex player says he’s on an upward trajectory heading into the new season.

“I’ve had a good season since Christmas,” he added.

“The first half of the year wasn’t too good but I’m moving in the right direction.”

Watch the World Snooker Championship live on Eurosport and Eurosport app from April 17- May 3