Liam Rosenior lashed out at an "indefensible" performance from his Chelsea side and said something must change "drastically" after they were thumped 3-0 by Brighton.

Chelsea's Premier League losing streak stretched to five games, their worst since 1993, as they were put to the sword at the American Express Stadium on Tuesday.

Ferdi Kadioglu, Jack Hinshelwood and Danny Welbeck scored for a dominant Brighton side, who leapfrogged Chelsea into sixth place.

Rosenior's team did not manage a single shot on target and have now failed to score in five consecutive league games, the club's worst run since November 1912.

Chelsea are now seven points off the top five with only 12 to play for, and the Opta supercomputer now assigns them just a 1.3% chance of Champions League qualification.

In addition to Aston Villa (98.9%), Manchester United (98.2%) and Liverpool (90.6%), Brighton (6.1%), Bournemouth (2.8%) and Brentford (1.8%) are viewed as more likely to qualify. 

Asked if he had just seen the worst performance of his three-month reign, Rosenior told Sky Sports: "By far. By far. It was unacceptable in every aspect of the game. 

"I keep coming out and defending the players, but that was indefensible, that performance tonight. 

"The manner of the goals we conceded, the duels that we lost... something has to change drastically right here, right now."

Asked what that change might be, Rosenior said: "We need to look in the mirror. I need to look in the mirror. 

"But I can't keep coming out here and defending some of the things that we're seeing. Against Manchester United, genuinely, the result wasn't there, but I felt we turned a corner. 

"But the general attitude and spirit was lacking – the determination from three or four of the starting 11. That's nowhere near enough for this club. 

"I can't come out and lie. I tell the truth. That was an unacceptable performance at every level."

Across each team's last nine games in the Premier League, only 18th-placed Tottenham (two) have won fewer points than Chelsea (five – W1 D2 L6). 

The Blues managed a meagre 0.04 expected goals (xG) in the first half of Tuesday's game, a lower tally than they recorded in any of Enzo Maresca's 114 halves of Premier League football at the helm. It was also their longest wait from kick-off (41 minutes) before attempting a shot in any game this season.

And at the other end, Chelsea have failed to keep a clean sheet in 12 Premier League games, their second-worst run in the competition, after a 13-match streak during 1996-97.