David McGoldrick extended dismal Derby's run without a league win to 35 matches with a smartly-executed goal in Southampton's 1-0 victory.
The 20-year-old Southampton striker pounced on the loose ball, after Adam Lallana had fired against the underside of the crossbar, to score the only goal of the game on 57 minutes.
It was McGoldrick's fourth goal in as many games this season, and secures Saints' first Championship victory under new manager Jan Poortvliet.
Derby have still not won a league match since Kenny Miller scored in a 1-0 Premier League win over Newcastle in September last year.
Roy Carroll superbly tipped strikes from Lee Holmes and then McGoldrick around the post early on, while Rob Hulse spurned three great chances.
McGoldrick netted on 57 and nearly bagged a second on 73, only to crash his shot against the crossbar.