Holders Ireland propelled themselves into pole position for further Guinness Six Nations glory following a dramatic opening round to this year's competition.
Andy Farrell's side claimed a stunning 38-17 bonus-point win over pre-tournament favourites France in Marseille on Friday night.
Italy then pushed England all the way before losing 27-24 in Rome while Scotland held off a second-half Wales fightback to prevail 27-26 in Cardiff.
Here we take a closer look at the three matches and highlight the impact made by some of the URC stars on the show.
France 17-38 Ireland
Ireland launched their title defence with a demolition of 14-man France.
Both sides went into the mouth-watering tournament curtain-raiser on the back of agonising World Cup quarter-final exits.
But tries from Leinster scrum-half Jamison Gibson-Park, Munster lock Tadhg Beirne, Munster wing Calvin Nash and Leinster hookers Dan Sheehan and Ronan Kelleher ensured it was the Grand Slam champions who bounced back at the first attempt.
France’s quest for victory at a largely subdued Stade Velodrome was damaged by the indiscipline of lock Paul Willemse, who was sent off in the 32nd minute following a high hit on Caelan Doris having previously been sin-binned for a similar challenge on another Leinster player, Andrew Porter.
Ireland, aided by 13 points from Munster fly-half Jack Crowley on his first Six Nations start, deservedly romped to another statement victory of the Farrell era.
Italy 24-27 England
Italy surrendered a half-time advantage as they went down to a narrow defeat against England in their opener at the Stadio Olimpico.
For only the third time in the history of a rivalry spanning 31 Tests, inspired Italy led at the interval but their 17-13 lead was methodically picked apart by Steve Borthwick’s men.
Benetton scrum-half Alessandro Garbisi, Tommaso Allan and Monty Ioane went over for tries for the Azzurri, with Allan adding two conversions and a penalty and Garbisi a conversion, but they had to be satisfied with a losing bonus point.
Wales 26-27 Scotland
Scotland ended 22 years of hurt in Cardiff after they thwarted a spectacular Wales fightback to win an extraordinary clash.
It was Scotland’s first victory in the Welsh capital since 2002 – ending a run of 11 successive defeats.
But Wales made them fight every inch of the way after the Scots had breezed into a 27-point lead after 42 minutes, with Edinburgh wing Duhan van der Merwe scoring two tries including a virtuoso long-range effort while Edinburgh prop Pierre Schoeman also touched down.
Captain Finn Russell kicked three conversions and two penalties but it only told half the story.
Cardiff flanker James Botham’s try sparked the Welsh recovery, and he was followed over the line by Rio Dyer (Dragons), Aaron Wainwright (Dragons) and debutant Alex Mann (Cardiff), with Ioan Lloyd (Scarlets) kicking three conversions.
Scotland found themselves on the rack after hooker George Turner and centre Sione Tuipulotu (both Glasgow Warriors) were sin-binned during the second period. Yet, they successfully closed the game out and left Wales wondering what might have been.