Second-half strikes from Tom Lawrence and Mason Bennett earned Championship side Derby County a deserved friendly win over Premier League opponents Southampton at Pride Park.
The warning signs were there for the top flight side as Derby had the best of the first half, and should have led before the interval but veteran David Nugent couldn't make Alex McCarthy work as his 45th minute lob sailed well over.
Southampton handed 45-minute debuts to new signings Mohamed Elyounoussi and Jannik Vestergaard, who played the first and second halves respectively.
Vestergaard had a chance to score his first Saints goal with 50 minutes on the clock, but his header from James Ward-Prowse's set-piece was well saved by goalkeeper Scott Carson.
The Rams were finally rewarded with almost an hour gone when Joe Ledley threaded through Lawrence, who kept his nerve to score past McCarthy.
Lawrence scored another just 13 minutes later with a low drive from the edge of the box, partly down to some lazy defending from the visitors.
Two Derby substitutes in Bennett and debutant Florian Jozefzoon combined to compound Southampton's misery with just under ten minutes remaining, with the latter having his shot well saved by McCarthy and the former popping up to put home the rebound.
Worrying signs for the Saints at both front and back
The main positive for Derby will be the performance of the 13-times capped Welshman Lawrence, who looked at his best while chipping in with two goals from midfield.
Derby fans, players and manager Frank Lampard will also be pleased with the effectiveness of their pressing game which worked so well against Premier League opposition.
Southampton have a lot less to be optimistic about, with their rearguard deficiencies rearing their ugly head yet again. Many thought the signing of Vestergaard from German side Borussia Mönchengladbach will have plugged the gap left by Virgil van Dijk since his January departure to Liverpool, but his natural pace and physique isn't easily replaced - as was shown by today's game.
While this match was just a pre-season friendly - games used to build fitness and team cohesion - the writing is on the wall for the South coast club after suffering from the same defensive problems last year.
There are also problems at the other end with Charlie Austin and Manolo Gabbiadini not looking sharp enough both in pre-season and towards the end of last season. Where will Southampton's goals come from?
Hughes will have three more games to work that out before Southampton start their Premier League campaign. They face Dijon FCO in France next week before matches at St. Mary's against Celta Vigo and Mönchengladbach.