But with the Blues, Chiefs and Hurricanes all having a game in hand there is plenty of scope for changes in the top four in the later rounds of the competition.
The Brumbies have 18 points, the Reds 17, Crusaders 15 and the Waratahs 11.
The Blues and Chiefs have nine points each and the Hurricanes eight.
Games from Round Four were:
Blues 32 Highlanders 20
Unsettled by a late revamp of their side due to Covid's intrusion, the Blues struggled for impact in the first half at Albany Stadium, conceding a penalty try and going to the break down 3-13. The Highlanders, desperate for a win, sensed their chance without setting the world on fire. The Blues stormed onto the field in the second half and moved the ball with more cohesion, wing Mark Telea twice creating opportunities on the right flank which were taken by blindside flanker Taine Plumtree for two tries within eight minutes. Then, skipper Dalton Papalii's sideline break provided a chance inside for unstoppable centre Rieko Ioane. The Highlanders gave themselves a sniff when consistent attacking as the Blues yielded red zone penalties saw flanker Shannon Frizell blast over. But the command shown by Blues first five-eighths Stephen Perofeta in the second half was rewarded when he slipped through to score the match-winner. They looked to have added a bonus point try with an intercept try to wing Caleb Clarke but it was ruled out and it was the 90th minute before the game finally petered out.
Blues 32 (Taine Plumtree 2, Rieko Ioane, Stephen Perofeta tries; Perofeta 3 con, pen; Zarn Sullivan pen) Highlanders 20 (Penalty try, Shannon Frizell try; Mitch Hunt con, 2 pen). HT: 3-13
Rebels 17 Brumbies 36
Bullocky No8 Rob Valentini opened the Brumbies scoring 15 minutes into the game with a hard-running burst for a try. The failure to tackle him was replicated 10 minutes later when mid-fielder Len Ikitau scored, largely as the result of the Rebels' failure to put fullback Tom Banks down during the run that ended when he passed inside to the unmarked Ikitau. Five minutes from half-time, a long pass from halfback Nick White running from a scrum, found wing Tom Wright unmarked close to the sideline to run in untouched. At the start of the second half Banks was allowed to run from his own 22 beyond halfway before putting in a grubber kick which was accepted by Wright for the simplest of tries. The Rebels had tighthead prop Cabous Eloff power over from a ruck. Flanker Jahrome Brown replied with a ruck try for the Brumbies before Rebels replacement Richard Hardwick benefited from quick hands inside him to race away for a try. The Brumbies managed an immediate response as prop James Slipper, standing off a ruck, fed a short ball to a flying Banks. He split the defence, turned on his after-burners and blasted over for the final try.
Rebels 17 (Cabous Eloff, Richard Hardwick tries; Matt To'omua 2 con, pen) Brumbies 36 (Rob Valetini, Len Ikitau, Tom Wright 2, Jahrome Brown, Tom Banks tries; Noah Lolesio 2 con; Ryan Lonergan con). HT: 3-17
Hurricanes v Moana Pasifika postponed.
Crusaders 21 Chiefs 24
The ramparts of the Crusaders' fortress took a pounding from the Chiefs' attack, eventually succumbing as the visitors claimed a 24-21 win in Christchurch. Forced to make 215 tackles to only 96 by the Chiefs, 23 by flanker Ethan Blackadder, 20 by lock Sam Whitelock and 19 by flanker Tom Christie, the Crusaders paid the price in the last 10 minutes as the Chiefs stormed home on the back of tries to outside backs Shaun Stevenson and replacement Rameki Pohipi. The statistics tell the story. The Chiefs made 169 carries to 85, they made 245 passes to 145 and they managed 17 offloads to eight. Most significantly, the Chiefs won 130 rucks to 61, and while they conceded 20 turnovers to 12, the gains were not enough to allow the Crusaders to build their usual comeback. Given the intrusion of Covid-19 into the Chiefs' selection, it was a triumph for the spirit of the young side on the back of some accurate goal-kicking from first five-eighths Bryn Gatland, who led the team well around the field. Hard running from No8 Pita Gus Sowakula (21 carries), lock Brodie Retallick (13), second five-eighths Quinn Tupaea (14), wing Alex Nankiville (12), fullback Emoni Narawa (11) and centre Anton Lienert-Brown (10) was a testament to the worth of ball retention and support.
Crusaders 21 (David Havili, Braydon Ennor tries; Richie Mo'unga con, 3 pen) Chiefs 24 (Shaun Stevenson 2, Rameka Pohipi tries; Bryn Gatland 3 con, pen). HT: 14-10
Reds 33 Fijian Drua 28
Fullback Jordan Petaia was on the end of a classic set-piece move inside the Reds half and he showed his speed to complete an outstanding try four minutes after the start. And while No8 Harry Wilson and hooker Josh Nasser (twice) carried the Reds to a 28-9 lead at the start of the final quarter, the Fiji Drua demonstrated why no side will be able to take them for granted. Three tries in five minutes, each of traditional Fijian flavour and none better than the second scored by replacement blindside flanker Joseva Tamani who latched onto a dropped Reds pass to streak 80 metres easily out-pacing the defence to score. Tied at 28-28, the Reds got home in the 78th minute when flanker Seru Uru was awarded a try. But it was vital goal-line lineout win in injury time was probably the more significant contribution to the final outcome.
Reds 33 (Jordan Petaia, Harry Wilson, Josh Nasser 2, Seru Uru tries; James O'Connor con, 2 pen) Fijian Drua 28 (Onisi Ratavi, Joseva Tamani, Vinaya Habosi tries; Teti Tela 2 con, 3 pen). HT: 15-6
Waratahs 22 Force 17
The Waratahs' looked set for a difficult day when wing Manasa Matele burst through their defence to score the first try nine minute into the game. But resorting to pressure through their pack, the Waratahs scored through flanker Charlie Gamble on the back of a driving maul. They claimed the lead at the end of the first quarter when fullback Will Harrison landed four penalty goals in the next 16 minutes, and capped a clever pass from halfback Jack Grant to score on halftime for a 22-7 lead. The second half provided no scoring action until six minutes from the end when Force prop Harry Lloyd bashed his way across the line. A conversion wasn't enough for a bonus point, but that came three minutes into injury time when Ian Prior landed a penalty goal.
Waratahs 22 (Charlie Gamble, Will Harrison tries; Harrison 4 pen) Western Force 17 (Manasa Mataele, Harry Lloyd tries; Jake Strachan con; Ian Prior con, pen). HT: 22-7