|Heineken European Champions Cup: Leinster v Ulster|
|Venue: Aviva Stadium, Dublin Date: Saturday, 30 March Kick-off: 17:45 GMT|
|Coverage: Live commentary on BBC Radio Ulster and the BBC Sport website|
Ulster's Rory Best says his side cannot shy away from the magnitude of the challenge they face when they take on Leinster in the last eight of the Champions Cup on Saturday.
The reigning champions have not lost a knockout game in two years.
"There is no point in trying to make the game into something that is isn't or trying to kid yourself," said Best.
"We know that they are a quality side and you have got to embrace that and see it as the challenge that it is."
Ulster impressed in the pool stages of this season's winning five of their six games, but will still travel to the Aviva Stadium as underdogs against a heavily-fancied Leinster.
Under the coaching leadership of Leo Cullen and Stuart Lancaster the province have re-established themselves at the forefront of club rugby in the northern hemisphere.
They enjoy an 18-point lead at the top of Pro14 Conference B having lost just three games in the competition this season.
"If this is the level you want to be at, you want to test yourself against the best," the Ulster captain insisted.
"They are arguably one of the best club sides there has ever been and it is a massive test for us."
Ulster's last inter-provincial European quarter-final was against Munster in 2012.
On that occasion the northern province produced a memorable display to claim an unlikely 22-16 win in Limerick.
"Some of our squad were still at school them, which is frightening," reflected Best.
"They are the sort of things that you can look back and lean on but ultimately what we did in Thomond Park doesn't have any bearing at all, bar that little bit of confidence from it."
In recent years Leinster have enjoyed the better of Ulster in knockout games, including victories over their provincial rivals in 2012 and 2013 finals.
'A monumental effort'
After a disappointing 2017-18 campaign, Ulster's progress under Dan McFarland is evidenced by their improved European performances and position in Pro14 Conference B.
Despite this, a win against Leinster in their first European quarter-final since 2013 would undoubtedly represent Ulster's most significant result for a number of years.
"To take a big step forward this weekend is going to take a monumental effort and it is going to take a big 80 minutes," said Best.
"The thing about Leinster is that even if you are playing really well, if you switch off for even just a moment they can produce something and that is the test - you have to be on your game right throughout it because one slip and this sort of team will score."