Many have tried but all have failed, with the Irish province unbeaten in 22 matches in the BKT United Rugby Championship and the Heineken Champions Cup.
They have won 21 of those, with only BKT URC title holders the DHL Stormers having managed a draw against them.
So how you get the better of the Dublin-based league leaders remains an unresolved issue, with former Munster and Ireland star Alan Quinlan the latest to address the matter.
Speaking at a BKT URC round table, the ex-back row man said: “Look, they are an outstanding side.
“Somebody asked me recently if they have any weaknesses and it’s hard to find any in their game at the moment. The run they have been on this year has just been unbelievable.
“They are very well coached and their squad depth means they have players that can seamlessly transition in and the quality stays the same. They have guys in their perceived second string that would make 90 per cent of professional squads across Europe.
“The pace of their game is just phenomenal. They are quick to everything and if they get tempo into their game they are so difficult to stop.
“Slowing them down and outmuscling them has to be your starting point. A couple of teams have done it. La Rochelle did it last season and Saracens a couple of years ago. That is the way you have to go. You have got to be really physical with Leinster. You have got to try and go after their set-piece and slow them down a little bit and then hopefully make a game of it.
“To beat them, you have got to be on it for 80 minutes and you have got to play at a high level right across your team because effectively they are an international side. They have unbelievable quality. They are a well-oiled machine at the moment.”
Reflecting on what underpins Leinster’s success, Quinlan said: “They are built on a really good schools system where players come out of those schools well developed and conditioned. There is a conveyor belt of these young players coming through.
“They have also done a wonderful job in recruitment and have really good staff behind the scenes. The system and the coaching there is superb.
“They seem to be the envy of a lot of teams across Europe. As a former Munster man, I am very envious of what they are doing! It’s phenomenal. You have got to give them credit.
“I think it’s a little bit unfair when people say they are winning just because of money. They have produced these players. The result of their success is they have 15-20 internationals and what their salary budget allows them to do - with the top-up from the IRFU for nationally contracted players - is retain those players.”
Table-topping Leinster round off their regular BKT URC season with two games out in South Africa, against the play-off chasing Emirates Lions and the Vodacom Bulls.
Looking ahead to Saturday’s fixture in Johannesburg, Quinlan believes this might be the point where the Irish giants’ unbeaten run comes to an end.
“I just have a feeling the Lions might produce a performance,” he said.
“The key for me is whether the Lions can keep with the pace of it. Power alone won’t win this because Leinster won’t lie down.
“But I just fancy the Lions may get a result against Leinster on Saturday.”