Chelsea recorded a sixth straight home win as an improved second-half display proved too much for Brighton at Stamford Bridge.
Antonio Conte’s side were frustrated in an opening period in which Tiemoue Bakayoko and Victor Moses went close.
But less than a minute into the second period Alvaro Morata headed his 10th Premier League goal from Cesar Azpilicueta’s fine cross before Alonso sealed victory in the 60thminute.
MANCHESTER UNITED 2-2 BURNLEY
Jesse Lingard came off the bench to spare Man United a Boxing Day defeat at the hands of Burnley, scoring twice to rescue a 2-2 draw for Jose Mourinho’s side.
Lingard answered a half-time SOS call with United staring down the barrel at 2-0 down but pulled one back with an instinctive back-heel before striking through a packed box in added time to cap a frantic finale.
HUDDERSFIELD 1-1 STOKE
Tom Ince’s first Premier League goal since February 2014 was cancelled out by Ramadan Sobhi’s second in four days as Huddersfield and Stoke drew 1-1.
Ince, who last registered a top-flight goal with Crystal Palace, finally ended his drought with his 45th shot in the division this season in the 10th minute.
WATFORD 2-1 LEICESTER
Watford came from behind to beat Leicester 2-1 and seal a first Premier League victory in seven games.
A tap-in from Molla Wague and an own goal from Kasper Schmeichel cancelled out Leicester forward Riyad Mahrez’s opener.
The victory was a first for Marco Silva’s side since a 3-0 success at Newcastle on 25 November.
WEST BROM 0-0 EVERTON
West Brom’s winless run stretched to 18 Premier League matches as they missed the best chances in a goalless draw at home to Everton.
Salomon Rondon and Craig Dawson both failed to hit the target from inside the six-yard box as the Baggies started strongly but could not find the net.
Toffees winger Yannick Bolasie played for the first time in over a year as he returned from a knee ligament injury, but he was unable to inspire his disappointing side before being substituted after an hour.
AFC BOURNEMOUTH 3-3 WEST HAM
Callum Wilson’s late equaliser salvaged a point for Bournemouth after an astonishing climax denied West Ham a rare win.
The Cherries forward controversially diverted a Nathan Ake header in, only to see the goal initially disallowed for offside – before referee Bobby Madley gave it.
West Ham were incensed by Madley’s decision, feeling not only that Wilson had been offside when Ake’s header skimmed across the goal, but also that his touch could have been handball.
The visitors had retaken the lead through two Marko Arnautovic goals inside the last 10 minutes after Ake had put the hosts ahead early in the second half.
James Collins had given the Hammers the lead early in the first half before Dan Gosling levelled before the break.
The result means Bournemouth remain third from bottom, a point and a place below West Ham.
Only a few minutes earlier, they had enjoyed a slice of luck, when Asmir Begovic slipped while trying to clear, allowing Arnautovic to round the home goalkeeper and slide the ball home to make it 2-2.
And just before the end of the 90 minutes, Begovic’s block to deny Javier Hernandez at close range landed perfectly for Arnautovic to score what David Moyes’ side must have thought was the winner.