Saracens will play in next weeks Champions Cup final after beating Munster 32-16 on Saturday.
There were tries from Rhodes and Vunipola plus twenty two points from the the boot of England flyhalf Farrell which seal the win for Saracens.
They made a great start with Farrell opening the scoreboard through a penalty.
Munster even things up again before Farrell added another two. Scores were even again when Conor Murray nailed a penalty from just inside the Saracens half but Farrell answered with another penalty before halftime.
Saracens dominated the second half and got the first try in the 43 minute when when they worked the ball through their hands on the left side and flanker Mike Rhodes found a gap in the Munster line to dot the ball down.
Farrell slotted another two penalties which saw Saracens with a 16 point lead before Munster came back at them.
Darren Sweetnam was at the end of their first try when Murray poached on the ball to get it out wide.
Saracens made sure of the win with Vunipola powering over the try line.
Saracens – Tries: Michael Rhodes, Billy Vunipola. Conversions: Owen Farrell (2). Penalties: Farrell (6).
Munster – Try: Darren Sweetman. Conversion: JJ Hanrahan. Penalties: Tyler Bleyendaal (2). Conor Murray.