The Reds made it a record seven wins on the trot after edging past the Waratahs 19-15 in Brisbane on Saturday.
It was the Queenslanders first win over their Australian rivals in seven years, with Reds pivot Quade Cooper providing a full house of points for his team.
Opposite number Kurtley Beale also contributed all of his team's points courtesy of five penalties, but in the end it wasn't enough as the men from Sydney slumped to back-to-back defeats.
More bad news for Waratahs fans, was the serious injury picked up by Australia wing Drew Mitchell. The 27-year-old fell awkwardly on his ankle after just 19 minutes and is now doubtful to make the World Cup.
The boot of Beale saw the Waratahs into a 9-3 lead early on, but Cooper cut the deficit with a penalty on the half-hour mark and seized control thereafter.
The Wallabies fly-half danced through the defence with a blistering break for the game's only try before adding the conversion and a drop-goal to leave it 16-9 at the break.
The second period proved a cagey affair, and committed Waratahs work at the breakdown earned a pair of penalties for Beale to bring his side to within a point.
However, as they became desperate in the closing stages Cooper punished an infringement close to half-way with a colossal kick to seal victory.
Pens: Cooper 3
Pens: Beale 5
Reds: 15 Ben Lucas, 14 Luke Morahan, 13 Anthony Faingaa, 12 Mike Harris, 11 Digby Ioane, 10 Quade Cooper, 9 Will Genia, 8 Scott Higginbotham, 7 Beau Robinson, 6 Radike Samo, 5 James Horwill (c), 4 Rob Simmons, 3 Guy Shepherdson, 2 Saia Faingaa, 1 Ben Daley.Replacements: 16 James Hanson, 17 Greg Holmes, 18 Adam Wallace-Harrison, 19 Liam Gill, 20 Leroy Houston, 21 Dom Shipperley, 22 Will Chambers.
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.
Date: Saturday April 23
Venue: Suncorp Stadium, Brisbane
Kick-off: 19:40 (09:40 GMT)
Referee: Steve Walsh (Australia)
Assistant referees: Ian Smith (Australia), Stephen Hill (Australia)
TMO: Steve Lesczcynski (Australia)