Chelsea's season slumped deeper into crisis after a 3-0 defeat to Brighton on Tuesday left its hopes of Champions League qualification hanging by a thread.

The result leaves Chelsea seventh in the Premier League and seven points adrift of fifth-place Liverpool having played a game more.

The top five qualify for the Champions League, but with just four more matches left to play, Chelsea is on the verge of being cut adrift.

Goals from Ferdi Kadioglu, Jack Hinshelwood and Danny Welbeck at the AMEX Stadium did not reflect the Seagulls' dominance on the night. Victory saw them leapfrog Chelsea and move up to sixth in the standings, boosting their own pursuit of European soccer next season.

"That was unacceptable in every aspect of the game. Unacceptable in attitudes. I keep coming out and defending the players, that's indefensible that performance tonight," Chelsea coach Liam Rosenior told Sky Sports. "Something needs to change drastically."

It was the seventh loss in Chelsea's last eight games in all competitions. The team that was crowned Club World Cup champion less than a year ago has only won one of its last nine in the league.

It has lost its last five without scoring, which, according to the league's official stats provider Opta, is its worst run since 1912 — the same year the Titanic sank.

Rosenior said the loss marked the most difficult night of his career.

"Some of the things I was witnessing today, I never want to see again," he said.

Chelsea — a team that cost in excess of $1 billion to assemble — is now left facing the likelihood of missing out on the lucrative Champions League.

While it has an FA Cup semifinal against Leeds on Sunday, its campaign has unraveled in recent weeks, including elimination from the Champions League at the hands of Paris Saint-Germain.

The decision to let go of Club World Cup-winning coach Enzo Marcesca in January now looks like a costly one, with his replacement Rosenior overseeing the team's slide.

"I've discussed in depth about, regardless of who's the manager, what needs to happen at this football club for it to be where it needs to be," said Rosenior.

"It's not about me. It's about this football club.

"Chelsea represents fight, spirit and determination, and that was lacking in every department this evening."

Asked how he can turn the tide at Chelsea, Rosenior said: "I have my own ideas, I am not here to make excuses. That was unacceptable from everyone involved, with me at the head of it. That needs to change.

"It was nowhere near the levels. Tackles, duels, intensity, spirit, energy, passion — all lacking, and that is the reason we lost.

"I will look at the team, will look at individuals and I will look at (putting together) a team I can trust to do the basics of football.

"It is something we have to adjust very quickly. It is accountability."

Liverpool plays Crystal Palace on Saturday and could move 10 points clear of Chelsea with a win.

Wrexham boosted

In the Championship, Wrexham took advantage of Hull's draw to move into the playoff spots on goal difference.

A 1-0 win against Oxford lifted Wrexham above Hull and into sixth in the standings with two rounds to go in the Championship. Josh Windass' goal in the 40th minute was enough to seal victory.

A 5-1 win for Coventry against Portsmouth confirmed the Championship title for Frank Lampard's team.