It put the Ospreys, whose squad is packed with more than a dozen Wales Grand Slam stars and overseas talent like Jackson's fellow New Zealanders Justin Marshall and Marty Holah, into next month's Twickenham final against Leicester.
But the Welsh region are also chasing a much bigger prize this season - Heineken Cup glory.
Saracens now block their path again on April 6, when they host the Ospreys in a quarter-final clash at Vicarage Road.
Saracens face a huge task, avenging their defeat in Cardiff - which was largely inspired by the brilliance of Wales backs Shane Williams and Gavin Henson.
Fly-half Jackson has no doubt the Ospreys are among the best sides he has played against - in northern and southern hemispheres.
He said: "They went into the game on a high following the Grand Slam. But that aside, I still think they are one of the best teams I have played against - both here and in New Zealand.
"They are very well-drilled and they have excellent players across the pitch.
"I would liken them very much to the Canterbury Crusaders. You play up against a very well-organised wall all day - and then when you make a mistake, they take full advantage."
The Crusaders won five Super 12 titles between 1998 and 2005, and they also landed the inaugural Super 14 crown in 2006.
In this season's Super 14, they boast a 100 per cent record after six games and hold an eight-point lead over their closest challengers - South African side, the Sharks.
"The Ospreys are a very sharp unit," Jackson added.
"They had a hunger and intensity level that was much higher than I think we've been used to seeing in the Guinness Premiership.
"We made mistakes, which made it easier for them, but you still have to give them a lot of credit for a good performance.
"But the beauty of rugby is that we are playing them in two weeks, which gives us a chance to put things right.
"We have got a lot of homework to do in looking at how we played against them - what went wrong and how best to combat them in a couple of weeks."