English Premier League table-toppers Chelsea were held to a 1-1 draw by Liverpool, but both Arsenal and Tottenham failed to make ground as the English Premier League title-race experienced another twist.
A David Luiz free-kick put the Londoners in front at Anfield in the 24th minute, only for Georgie Wijnaldum to equalise in the 57th minute.
Both teams had chances to win the match, with Liverpool goalkeeper Simon Mignolet saving a penalty from Diego Costa in the 76th minute and Roberto Firmino missing a header for the home team late in the match.
But it was disaster for Arsenal, as they went down 2-1 to Watford at the Emirates Stadium.
The Hornets had not won a league game since December 10, but raced into a two-goal lead, courtesy of a deflected Younes Kaboul strike and a Troy Deeney tap-in.
With Arsene Wenger in the stands, as he served the second of a four-match touch-line ban, the Gunners rallied after a dismal first half, but could not build on Alex Iwobi's effort, as the visitors hung on for a 2-1 win.
The result was Arsenal's first defeat of 2017 and adds even more significance to Saturday's showdown with leaders Chelsea at Stamford Bridge.
Shkodran Mustafi fouled debutant M'Baye Niang and Kaboul's drive from the resulting free-kick took a huge deflection off Aaron Ramsey and flew past Petr Cech.
The second Watford goal followed shortly afterwards, as Etienne Capoue broke forward, eased past Mustafi and, although his effort was saved by Cech, Deeney was on hand to snaffle home the rebound.
Arsenal's goal came from a Alexis Sanchez cross to Iwobi, who netted.
Spurs played out a disappointing goal-less draw with Sunderland away from home and missed an excellent chance to cut the lead on Chelsea.
In other matches, Swansea City beat Southampton 2-1, Middlesbrough drew 1-1 with West Brom, Crystal Palace defeated Bournemouth 2-0 while Burnley beat defending champions Leicester City 1-0.