The Reds ended their losing streak against the Waratahs and won their seventh match in a row when they beat the Waratahs 19-15 in Brisbane.
The Reds had not beaten the Waratahs for seven matches over six years and the Reds have never won seven matches in a row.
The Reds showed glimpses of their usual flashy brilliance in attack with the best example being when Quade Cooper broke through the Waratahs defence but the match was won by the an enormous defensive effort from the Reds.
For most of the second half the Waratahs dominated territory and possession and spent almost 20 minutes on the Reds tryline but their defence was second to none as the Waratahs sent wave after wave of attack at the Reds.
The Reds have now opened up an 11 point lead over their nearest rivals in the Australian conference and having led the Super Rugby standings for the last three weeks have proved they are a title contender with substance.
After leading 16-9 at halftime, the Reds had to withstand a second half onslaught from the Waratahs before sneaking home by four points to maintain their place at the top of the Super Rugby standings.
The Reds turned in a magnificent second half defensive effort to deny the visitors a win, somehow keeping their line intact despite the Waratahs having almost 80 per cent of possession and field position in the second half.
The Waratahs used their superior scrum to try and batter the home side into submission, but despite looking certain to crack throughout the second half, the Reds hung on grimly for their seventh win in a row, a first in their Super rugby history.
The Reds had opened the match full of intent and were first on the scoreboard thanks to a Quade Cooper penalty in the eighth minute.
However two quick penalties to Cooper's opposite number Kurtley Beale put the Waratahs into the lead.
The visitors suffered a huge blow minutes later when in-form winger Drew Mitchell badly injured his ankle and was carried from the field on a stretcher.
Beale made it 9-3 with another penalty, before a second three-pointer to Cooper narrowed the gap.
The Wallaby flyhalf then produced some of his trademark magic after Beale put the restart out on the full.
From the ensuing scrum, Cooper took the ball 55 metres out and split the Waratahs defence before palming off Daniel Halangahu to touch down beside the posts, celebrating with a double backflip to the delight of the 40,000 fans.
He then rubbed salt into the Waratahs' wounds with a drop goal in the 40th minute to send the Reds into the break seven points clear.
Beale kicked a fourth penalty goal soon after the resumption, which signalled a 30-minute period of complete Waratahs domination.
The Waratahs should have scored a number of times but were held out by some superb Reds defence and some poor decision-making of their own.
Waratahs captain Phil Waugh turned down numerous kickable penalties, banking on his team's dominance in the scrum, but they were unable to cross the Reds line.
With eight minutes to go, the Waratahs finally opted to take the points on offer when they were awarded a penalty right in front, Beale slotting it home to close the gap to 16-15.
But Cooper, who had a mixed game despite his first half brilliance, closed the match out with a 45-metre penalty to trigger wild celebrations from the Reds players.
Final Score Reds 19 Waratahs 15
Tries - Q Cooper
Pen - Q Cooper 3
Con - Q Cooper
Drop - Q Cooper
Pen - K Beale 5
Referee: Steve Walsh (Australia)
Assistant referees: Ian Smith (Australia), Stephen Hill (Australia)
Television match official: Steve Lesczcynski (Australia)
Reds : 1. Ben Daley , 2. Saia Faingaa , 3. Guy Shepherdson , 4. Rob Simmons , 5. James Horwill (c) , 6. Radike Samo , 7. Beau Robinson , 8. Scott Higginbotham , 9. Will Genia (vc) , 10. Quade Cooper , 11. Digby Ioane , 12. Mike Harris , 13. Anthony Faingaa , 14. Luke Morahan , 15. Ben Lucas
Replacements : 16. James Hanson , 17. Greg Holmes , 18. Adam Wallace-Harrison , 19. Leroy Houston , 20. Liam Gill , 21. Will Chambers , 22. Dom Shipperley
Waratahs : 15. Lachie Turner , 14. Tom Kingston , 13. Ryan Cross , 12. Tom Carter , 11. Drew Mitchell , 10. Kurtley Beale , 9. Luke Burgess , 8. Wycliff Palu , 7. Phil Waugh [c] , 6. Ben Mowen , 5. Sitaleki Timani , 4. Dean Mumm , 3. Sekope Kepu , 2. Tatafu Polota-Nau , 1. Benn Robinson
Replacements : 16. John Ulugia , 17. Al Baxter , 18. Kane Douglas , 19. Dave Dennis , 20. Pat McCutcheon , 21. Brendan McKibbin , 22. Daniel Halangahu.