Two Republic of Ireland internationals were on target on a busy day of Premier League action on St Stephen's Day.
Youngster Michael Obafemi - aged 19 - opened the scoring for Southampton in their valuable 2-nil win over Chelsea at Stamford Bridge.
Obafemi's fine left-footed strike came in the 31st minute, and was added to by a Nathan Redmond goal in the second half to give Southampton a priceless three points in their battle to move away from the relegation zone.
The Saints are now up to 14th, three points above the drop zone.
Elsewhere, Conor Hourihane's goal helped Aston Villa overcome Norwich by a goal to nil.
His 64th-minute effort was enough to give Villa all three points, though Dean Smith's side remain in the bottom three in 18th.
Elsewhere on a busy afternoon of action, both Mikel Arteta and Carlo Ancelotti were in charge of their new clubs for the first time.
Ancelotti's Everton beat Burnley 1-nil at Goodison Park - with Dominic Calvert-Lewin's 80th minute goal the difference.
— Southampton FC (@SouthamptonFC) December 26, 2019
There was no opening day win for Mikel Arteta, however,
His Arsenal side showed well for long stages but were held to a 1-all draw with Bournemouth at the Vitality Stadium.
The Gunners needed Pierre Emerick Aubamayang's second-half equaliser after Dan Gosling gave the home team the lead after 35 minutes.
Tottenham are into fifth after a 2-1 comeback win over Brighton in the lunchtime game.
Sheffield United dropped back into sixth after they failed to beat bottom-club Watford at Bramall Lane.
Gerard Deulofeu gave the Premier League strugglers the lead, but Oliver Norwood equalised from the penalty spot before the break.
However, Watford held on to earn a point.
In the day's other game, Crystal Palace came from behind to overcome West Ham 2-1 in their London derby.
Robert Snodgrass gave the Hammers the lead, but goals from Cheikhou Kouyate and Jordan Ayew helped Palace move up to ninth; West Ham are in 17th.