Southampton were dumped out of the Carabao Cup after a 3-1 first-round defeat at League Two Gillingham as Robbie McKenzie scored twice.

McKenzie doubled Gillingham’s advantage six minutes into the second period, before volleying into the net 20 minutes from the end to secure the Gills’ place in the second round for the fifth successive campaign.

Carlos Alcaraz claimed a consolation goal for Southampton with a minute left, but it was too little too late.

Saints were semi-finalists in the competition last season and were appearing in the first round for the first time since 2011-12 following their relegation from the Premier League last season.

Boss Russell Martin changed his entire starting 11 from the side that beat Sheffield Wednesday on the opening day of the Championship campaign.

Midfielder Shea Charles made his debut following his summer transfer from Manchester City and Romain Perraud returned from the injury that ruled him out at the end of last season.

Yet it was Gillingham who dominated the opening period with Shadrach Ogie and Ethan Coleman both heading over either side of Nadesan’s opener.

Sekou Mara hit the woodwork for the visitors, but defender McKenzie made it 2-0 after 51 minutes when Southampton failed to deal with Cheye Alexander’s set-piece.

Ogie picked up the ball at the back post before Max Ehmer got the crucial flick-on to McKenzie, who had the softest of touches to edge it past Alex McCarthy.

McKenzie added his second with a sweet strike after Max Clark corner’s dropped to him.

Alcaraz’s late deflected shot from distance was not enough to save the Saints from failing to progress beyond the first round of the competition for the first time since the 2006-07 season.

Gillingham manager Neil Harris said:

“It couldn’t have gone any better. It’s a great result and the performance was excellent. If anything, the win should have been by more than two goals.

“Southampton are a top side, even with the changes. I wanted to play on the front foot. We dominated the first 15 minutes, during which we could have scored more than one, and ultimately for 75 minutes we bossed it.

“The cup competitions aren’t the priority, but that doesn’t mean we don’t want to win. We want to be competitive, we want 8,000 people to appreciate that, and we’ll do the same in the next round.”

Southampton manager Russell Martin told BBC Radio Solent:

“It’s the most disappointed I’ve been in the six weeks I’ve been here which is a really obvious statement.

“There’s some positives to take with the young guys when they came on, Sam Amo, Kammi (Kamari Doyle) when he came on, Tyler [Dibling] gets an appearance as well.

“Stuey Armstrong was great, 45 minutes which was the plan to build him up minutes-wise as he’s missed a lot. Joe Aribo, the same. I’d have loved to have those guys on the pitch for longer, Sekou [Mara] as well.

“I think it’s a big lesson for Sekou and a few of the guys, you need to be all-in in being a professional. All-in, the way you train, the way you play. Don’t train one way to play another, train the way we train, we work the way we work so we can go out on the pitch and deliver a certain level of performance.

“And tonight we had too many people that didn’t really. Too many that just weren’t brave enough to play or didn’t want to play the way we really want them to play the first 20 minutes and we paid for that conceding a really poor goal.

“We had nine players who played in the Premier League on the pitch, who I presume would deem themselves Premier League players. You have to be better than that. We showed fight in the last half an hour and it was too late by that point.”