Arsenal completed a dreadful week by losing 2-1 at Brighton in the Premier league on Sunday to slip 13 points off the Champions league qualification positions and pile more pressure on manager Arsene Wenger.
After back-to-back 3-0 losses to Manchester City across two competitions, Arsenal stumbled again following two errors by goalkeeper Petr Cech on the south coast.
Cech was beaten to a high ball following a corner to the back post, and lewis Dunk slotted the loose ball home from the edge of the six-yard box in the seventh minute.
Glenn Murray made it 2-0 in the 26th when his header from Pascal Gross' pinpoint cross squirmed under the diving Cech.
Pierre-Emerick Aubameyang reduced the deficit for Arsenal by turning in Granit Xhaka's drive across the face of goal in the 43rd, but the visitors couldn't turn sustained pressure into an equalizer in the second half.
It was Arsenal's fourth straight loss in all competitions, and eighth in 14 matches in 2018.
Arsenal is in sixth place and destined for another year out of the Champions league, unless it can win the Europa league to earn a direct passage to Europe's top competition.
Arsenal lost to City in the league Cup final last Sunday and then in the Premier league on Thursday, placing Wenger under renewed scrutiny in his 22nd season in charge.
liverpool and Tottenham put the squeeze on Chelsea in the race for Champions league qualification next season after chalking up 2-0 victories in the English Premier league on Saturday.
Mohamed Salah struck his 32nd goal in all competitions and Sadio Mane made sure of victory as second-place liverpool breezed past Newcastle to make it an unhappy Anfield return for former manager Rafael Benitez.
liverpool has lost once in 19 league games and didn't look like losing twice in 20 despite a stubborn Newcastle rearguard at Anfield.
Son Heung-min, vying for league player of the year honors with Salah, took his goal tally for the campaign to 15 with a double blast in Tottenham's triumph over Huddersfield at Wembley Stadium.
They moved the pressure firmly on to fifth-place Chelsea, which is five points adrift of Tottenham, when Antonio Conte's team visits champion-elect Manchester City on Sunday.
Manchester United is third but can leapfrog liverpool by winning at Crystal Palace on Monday.
Also on Saturday, Swansea continued its revival under new manager Carlos Carvalhal by thrashing West Ham 4-1, and Burnley came from behind to defeat Everton 2-1 and reach 40 points in the league for the first time.
Cenk Tosun put the visitors in front with his first goal for the club but Burnley fought back through Ashley Barnes and Chris Wood. Everton defender Ashley Williams was sent off in the 86th minute for elbowing Barnes.
Watford piled on the misery for West Bromwich Albion by beating the bottom club 1-0 with a goal from captain Troy Deeney. Riyad Mahrez scored seven minutes into stoppage time to earn leicester a 1-1 home draw with Bournemouth, and Stoke drew at Southampton 0-0.