The openside scooped the Guinness Man of the Match award as last season’s champions secured a 24-9 win over Munster at the RDS Arena in their semi-final.
Tries from Sean Cronin and James Lowe, along with 14 points from the boot of Ross Byrne, ensured they would have a shot at successive titles.
And Van Der Flier, playing his first game since getting injured while playing for Ireland against France in the Guinness Six Nations in March, is under no illusions about the task ahead of them as they look to lift the trophy.
“We have to dust ourselves off now and prepare to play Glasgow in Glasgow, which is going to be incredibly tough,” he said.
“Celtic Park will be a special place to play as well, so it will be a good week.”
— Leinster Rugby (@leinsterrugby) May 18, 2019
One advantage Leinster won’t have in next weekend’s title decider will be the home crowd, which Van der Flier believes was one of the differences in the semi-final.
The flanker is convinced the crowd willing them on helped the hosts to gain the upper hand – as they pulled away in the final quarter of the match.
“The crowd played a massive part,” he added. “To be at home at the RDS is very special. They were incredible.
“Munster are an incredibly good team and it was always going to be tight.
“We did well to pull away in the second half but it was one of the toughest games I’ve played in, which is a credit to Munster. We are delighted to win.”
Munster coach Johann van Graan said he could not fault the effort of his men, with fly-half – and former Leinster man – Joey Carbery registering all their points with three successful penalties.
But he rued the number of penalties conceded as they lost out to the champions in the knockout stages for a second year in a row.
Van Graan highlighted Leinster’s ability to make the most of Niall Scannell’s yellow card, which he received when a pass from Luke McGrath hit him while retreating.
A tough way to end the campaign.
Very proud of everyone in red today and throughout the season.
— Munster Rugby (@Munsterrugby) May 18, 2019
“I thought we played some very good rugby in the first half but they got a penalty on the stroke of half-time to give them a three-point lead,” he said.
“Straight after half-time we conceded that [Scannell’s] yellow card and on the tenth minute of that card they scored the try.
“We were behind 19-9 to and the penalty count was something like 13-6. You can’t concede that many penalties in an away semi-final.
“I can’t fault the attitude, they gave it all out there, unfortunately we were beaten by a better team out there on the day.”
Munster skipper Peter O’Mahony echoed the sentiments of his coach.
“You can’t come somewhere like Leinster and concede 13 penalties,” he added.
“A lot of them were in crucial moments – either they were kickable or when we had them under pressure in their 22 as a big release valve.
“We’ve had huge positives this year, taken big steps forward, as have other teams. We are doing a lot of things right but we just need to figure out where we can get an extra per cent or two.”
The Guinness PRO14 Final is one of the most entertaining games in the rugby calendar and takes place in Glasgow’s Celtic Park on May 25. Tickets start at just £25 for adults, £1 for kids. Visit www.pro14rugby.org/finaltickets