The Reds won the Australian Super Rugby conference and booked a home quarter final when they beat the Waratahs with a bonus point 32-16 in Brisbane.
The victory was the Reds sixth in a row and extended the Waratahs losing streak to a record eight straight losses.
The Reds started the weekend in eighth place but moved into third place as conference winners after the Blues beat the Brumbies earlier in the day.
Before the Brumbies loss the Reds were hoping that they could sneak into the play offs if results went their way provided they beat the Waratahs with a bonus point.
However few expected the Blues to upset the Brumbies at home and that result gave the Reds the opportunity to sneak ahead of the Brumbies by virtue of them having more wins.
The Reds made their intentions known almost from the kick as they scored the first of their tries in the third minute when Scott Higginbotham crossed the tryline.
The Reds were too committed for the Waratahs and outscored their opponents by five tries to two.
It was only the second time in Super Rugby that the Reds had claimed a bonus point against the Waratahs.
The Reds head into next weekend's opening playoffs as the third-ranked team and will have home advantage against the team that finishes sixth in this weekend's final regular round.
But they could be without star playmaker Quade Cooper, who received a yellow card and was also put on report by referee Steve Walsh for a high tackle that forced a dazed Berrick Barnes from the field.
The Reds wrapped up their bonus point with their fourth try from winger Dom Shipperley in the 50th minute to add to tries from Higginbotham, Liam Gill and James Slipper. Skipper Will Genia added a fifth.
"The four-try bonus point was not so much an obstacle for us but a challenge and our intent was just to win the game and we were looking to playing well," Genia said.
"We always thought it was possible, there was a lot of people who didn't.
"We had a rough patch towards the middle of the season and we had players coming back from injuries and we started to build a bit of momentum and we got back into our rhythm."
It was a dismal end to a woeful campaign for the Waratahs, who lost their last eight games.
"We're very disappointed with tonight's performance. It's the story of our season. There were patches where we played really good rugby but we just let teams in," Waratahs skipper Benn Robinson said.
"It's the small errors that really hurt our game: dropped ball, turnover lineouts at crucial times where teams get on top of us."
The Waratahs were well in the contest trailing 12-11 at halftime in Brisbane but the Reds blew the game wide open with three tries in the next 20 minutes to lead 29-11 and were never under threat from there.
Final Score Reds 32 (12) Waratahs 16 (11).
Tries - S. Higginbotham, L. Gill, J. Slipper, D. Shipperley, W. Genia
Pen - M. Harris
Con - M. Harris 2
Cards - Q.Cooper (yellow and white)
Tries - D. Mitchell, T. Carter
Pen - B. Foley
Drop - A. Ashley-Cooper
Referee: Steve Walsh
Assistant Ref 1:Andrew Lees
Assistant Ref 2:Angus Gardner
TMO : Steve Lesczcynski
1. Greg Holmes, 2. Saia Faingaa, 3. James Slipper, 4. Rob Simmons, 5. Adam Wallace-Harrison (vc), 6. Jake Schatz, 7. Liam Gill, 8. Scott Higginbotham, 9. Will Genia (c), 10. Quade Cooper, 11. Digby Ioane, 12. Mike Harris, 13. Anthony Faingaa, 14. Dom Shipperley, 15. Luke Morahan.
Reserves: 16. James Hanson, 17. Ben Daley, 18. Radike Samo, 19. Beau Robinson, 20. Jarrad Butler, 21. Ben Lucas, 22. Ben Tapuai.
15. Adam Ashley-Cooper ,14. Lachie Turner ,13. Rob Horne ,12. Berrick Barnes , vice captain,11. Drew Mitchell ,10. Bernard Foley ,9. Grayson Hart ,8. Dave Dennis ,7. Chris Alcock ,6. Dean Mumm ,5. Kane Douglas ,4. Sitaleki Timani ,3. Paddy Ryan ,2. Tatafu Polota-Nau ,1. Benn Robinson , captain
Replacements:,16. John Ulugia ,17. Jeremy Tilse ,18. Lopeti Timani , 19. Jono Jenkins ,20. Brendan McKibbin ,21. Tom Carter ,22. Tom Kingston