In an Ashes series riddled with low-quality cricket, England's Jamie Smith managed to find new depths. Smith's dismissal on the second morning of the fifth Test against Australia was called "one of the worst I have ever seen" by BBC chief cricket commentator Jonathan Agnew.

Former England fast bowler Steven Finn, commentating on TNT, said it was "completely brainless". With lunch approaching in Sydney and Australia attempting to burgle some overs to hasten the second new ball, the hosts asked Marnus Labuschagne to bowl some of his very occasional medium-pace. Smith had moved to a sketchy 46. His partnership with Joe Root - unbeaten with a masterful century - was worth 94. Australia, without a specialist spinner, were employing the part-time off-breaks of Travis Head at the other end.

Labuschagne had 13 previous Test wickets to his name, all taken bowling spin. He laid a blatant trap, with seven fielders back for him to bowl some gentle bouncers. "We better describe this field, because it is remarkable," said Agnew on Test Match Special. "Marnus Labuschagne usually bowls wrist-spin but is being employed here as a bouncer bowler. And there is nobody within reach of the batsman. "You cannot be bounced out by Marnus Labuschagne in a Test match! This is just a bizarre passage of play."

Somehow, Smith obliged. From the fourth ball Labuschagne bowled, the England wicketkeeper stepped back and attempted a flat-batted swipe. He succeeded in picking out Scott Boland, the only fielder in front of square on the off-side, at cover. In doing so, he became victim to one of the most staggering dismissals of an England batter in Test cricket, one that perfectly encapsulates the slapdash nature of their Ashes series defeat.

"No. No!" exclaimed former England fast bowler Agnew. "I have seen a lot of cricket and that is one of the worst dismissals I have ever seen." Alex Hartley, a Women's World Cup winner with England in 2017, added: "That is filthy. Absolutely filthy. It is disgusting. "We literally just said you cannot get out to this filth and he has given his wicket away. What is that?! That is just a lack of discipline."

Finn, who won the Ashes with England on the 2010-11 tour of Australia, went further when he said: "That's completely brainless. I cannot believe what I've seen there. That's going to be a very quiet dressing room for Jamie Smith to walk back into." It ended a skittish innings from Surrey's Smith, who could have been dismissed by Cameron Green on a number of occasions before Labuschagne was brought into the attack.

On 22, Smith was caught at cover, only for replays to show Green overstepped. Next ball, Smith slashed between wicketkeeper Alex Carey and Beau Webster at first slip. Smith also top-edged Green over the slips when he had 30 and, on 34, miscued a pull that just evaded mid-on.

This latest horror show in Sydney comes at the end of an incredibly disappointing Ashes for Smith, continuing a poor run of form that began in the home summer. After Smith made an astonishing 184 in the second Test against India at Edgbaston in July, his batting average stood at almost 59. Eight matches later, it has fallen to 42. He has passed 50 only once in Australia.

In the first Test he did not adapt to the large boundaries in Perth and was bounced out. In the second Test in Brisbane, his first match with a pink ball, he missed two crucial chances behind the stumps. The 25-year-old's 60 in the second innings of the third Test in Adelaide was his highest score of the series, yet he holed out off Mitchell Starc just as he was giving England hope of an unlikely run-chase. Before the fifth Test in Sydney he was left out of England's white-ball teams for the upcoming tour of Sri Lanka and the T20 World Cup that follows.

Smith still has the second-highest batting average for a gloveman that has kept in at least 20 Tests for England, but his collapse in form could leave a doubt over his place for the home summer. "Jamie Smith is nowhere near the rhythm he should be," said former England captain Michael Vaughan. "This England team have to start to learn and accept. I read something that said Jamie Smith will probably get a pat on the back for trying to take the game on. "That is the culture that is being created in this England side and that is why they have failed on this tour. There are times to get on the front foot but when it is so close to lunch and Marnus Labuschagne is bowling bouncers. I cannot accept that. It sums up this England side."