Where to start? Connacht's fabulous win that marks them out as now looking like they belong in a competition that they struggled to get into for so long?
Ulster's demolition job away to the finalists of two seasons ago? Munster's return to familiar ways in accounting for high flying Saracens? Or Leinster's brutal bout at the fortress that is Stade Marcel Michelin (now I'm running out of question marks)?
It was close to being the perfect weekend in Europe for Irish teams. As the Scots and Welsh (who must be getting really concerned at how their regions are disintegrating in the face of the French financial might) implode, the Irish teams stand alone in bearing the Rabodirect Pro12 flag at the top table.
For the first time ever all four Irish provinces are in contention to qualify from their groups after three rounds of the tournament. However, for all bar Ulster, the work really does start now.
Ulster and Connacht got the weekend off to a flying start with emphatic wins over quality opponents in Northampton and Biarritz respectively. With their 13th consecutive win, Ulster have really signalled their intent to use last season's final as a springboard rather than a destination.
With the luxury of being able to leave one of Europe's form players in Craig Gilroy on the bench, even that decision looked justified as both Andrew Trimble and Tommy Bowe weighed in with tries.
Whatever about their wings, at fullback Jared Payne's play is such that Rob Kearney must be getting a bit anxious about Payne only having one year left to qualify to be eligible for Ireland. He looks at times to be playing the game at a different pace to those around him such is his composure.
Up front, Iain Henderson continues to develop at a pace that leaves the absence of Stephen Ferris less of a burden than it would otherwise be, while Darren Cave and Paddy Wallace threw down reminders of their worth to Declan Kidney.
With 16 tackles, Rory Best did likewise in a weekend when both Leinster hookers demonstrated vulnerability under pressure. While Northampton will undoubtedly pick themselves up this weekend, an evening time fixture under the lights in Ravenhill against a rampant Ulster may go horribly wrong for them if the home team gets off to a good start.
And it looks like they may be missing their hooker Dylan Hartley for the event as he has been cited for striking his opposite number with his arm. This continues his disciplinary problems with Irishmen as he was previously suspended for gouging against Jonny O'Connor (and James Haskell) and biting Stephen Ferris.
For Connacht, what joy as they dismantled one of the big French sides, replete with star names. The signing of Dan Parks looked a tidy bit of business at the time and it is proving inspired. Parks gives them an assurance and direction that comes from having spent considerable time making decisions at the top end of the game.
The real surprise was that the first of his two drop goals was his first for the province for this prolific drop gaoler. With exciting young talents liberally sprinkled through the side in such as Dave McSharry, Robbie Henshaw, Tiernan O'Halloran and Kieran Marmion, Eric Elwood's side is fulfilling its mandate for Irish rugby.
A prime example is Eoin McKeon, a native 'Wegian who is coming through to the first team at number eight. He must have been brought on a ton by playing against Imanol Harinorduquy when the French star came on in a desperate attempt to stem the flow. And trying to back it up away in Parc des Sports Aguilera will be a further chapter in the education.
Munster were a curious mix of new and old style as they deservedly came through against Sarries. At times they carried up front and at times the second rows were to be found out on the wing again.
And at times they looked good, without ever really being able to break free. Nonetheless, and despite conceding what may prove a valuable bonus point in the dying minutes, they got the job done.
Ronan O'Gara once more reminded people of his quality, as did Conor Murray who has come back very strong from his nightmare moment away to Racing Metro. For me, however, the player that made the greatest impression was David O'Callaghan at blind side.
He really looked like a player that has come of age and was now making his mark rather than just surviving at the top level. Others to perform well included James Downey, who is starting to look like the player they wanted him to be, James Coughlan, who continues to outpunch his weight alongside the physical Peter O'Mahony, while Dave Kilcoyne's maintained his progress this season. In the absence of a forward leader like Paul O'Connell you can also really see the increased influence of Donncha Ryan, who is having a fantastic season.
Sunday is almost certainly the pool decider, though Sarries still have to go to Racing Metro on the last day. Munster appear to have the more rounded game of the two sides, but with their hard core of South Africans, Saracens are a hardy nut to crack.
In Alex Goode they have a class operator at fullback, in a pacey back three but they don't get used as much as they might. Munster got at the Saracens lineout at the weekend but with an experienced campaigner like Steve Borthwick in charge, that will likely be rectified. Munster will have to produce some big D and take what chances they get if they are to get the necessary win. It's as big an ask as they used to deliver on in the old days.
For Leinster, there was the scent of a victory as good as any they have achieved despite the absence of O'Driscoll and Kearney and the presence of an under-cooked Sean O'Brien. That said, the Tullow Tank looked in fine fettle in a real potboiler of a match.
Clermont were stymied by Leinster's defence but when the match was really in the melting pot they upped their own defensive intensity to astonishing levels. Around the hour mark they threw themselves at Leinster with a ferocity that made possession a liability and probably made the difference in the end.
Jonny Sexton's cross kick for Fergus McFadden was a pivotal moment. When you look at the replay you can see why Sexton went for it. McFadden was a good fifteen yards wider than Naipolioni Nalaga when he looked up. However, Nalaga made excellent use of the ball travelling time to make up the ground and foil the typically committed attempt of McFadden.
Leinster played well, demonstrating an admirable capacity to retain possession in the face of a committed defence. However, they continued to struggle to create real openings.
Clermont will be mightily relieved that their 50 match unbeaten home record is intact. Vern Cotter is correct when he says that Leinster are under pressure this weekend. This is true. However, I am reminded of the story of the Chinese general Xiang Yu.
On the morning of a key battle his troops awoke to see their ships burning. They hurried to their feet to fight off the attack but soon discovered that Yu himself had destroyed their ships and that he had also ordered the cooking pots crushed. Yu explained to his troops that without the ships or cooking pots they had no choice other than to fight their way to victory or perish. His army duly won a comprehensive victory and went on to win a further nine consecutive battles in obliterating the Qin dynasty.
Figuratively speaking, Leinster haven't got a pot to cook in and so must win, which I believe they will do. However, they will also realise that Exeter and the Scarlets are unlikely to manage any favours on their behalf, and pursuing a top two runners up spot is also fraught with difficulty.
So Leinster will be going all out to deny Clermont a losing bonus and get one for themselves. I expect them to throw the kitchen sink at a team that has struggled for away wins in the Top 14 this season, achieving their three away wins only against three of the league's bottom four sides and going down to Castres, Toulouse and Montpellier. It's may be madness, but I wouldn't rule out a five-pointer for Leinster backed by a full house at the Aviva.