The Crusaders lost their unbeaten record but still lead by six points after Super 14 title rivals the Sharks missed their chance to close the gap, losing to the Brumbies this weekend.

The six-time southern hemisphere provincial champions crashed to their first loss of the campaign to fellow New Zealanders Chiefs 18-5 in Hamilton on Friday, opening the door for the Sharks to make up ground.

But the Sharks frittered away an 18-7 half-time lead and lost their way in the second half with two yellow cards in self-destructing to a 27-21 defeat to the Brumbies in Canberra.

While the leaders faltered in an extraordinary week 10, Waratahs, Stormers and the Chiefs pressed their claims for next month's playoffs.

The Waratahs won their fourth straight game, 26-3 over last-placed Golden Lions in Sydney to climb to third, one point behind the Sharks, while the Stormers scored a fifth win in six matches, 20-12 over Hurricanes, to move into fourth spot.

The Chiefs, gaining a head of steam after their fourth consecutive victory, are level with the Stormers on 27 points, but just out of the top four on scoring percentages.

The Hurricanes, the Blues, who had this weekend off, and the Brumbies, are still in the semifinal mix, but Australia's Western Force saw their chances hit with a 29-12 loss to Reds in Brisbane on Friday.

In a match of no playoff bearing, the Bulls ended a five-match losing streak with a 47-17 victory over the Highlanders at Loftus Versfeld.

The Crusaders never recovered from an 18-0 half-time deficit to lose their aura of invincibility and relinquish their eight-match winning sequence to the fast-improving Chiefs.

Flyhalf Stephen Donald was outstanding, having a hand in his side's two tries and kicking two penalties and a conversion.

Intense Chiefs' pressure stripped the Crusaders of their usual composure and they failed to make the most of their chances.

Yet the Sharks could not take advantage the following night in Canberra, blowing a handy lead and gifting the tenacious Brumbies a victory to also drop their first match.

Last year's beaten finalists looked set to stay unconquered after a composed opening half, but the Brumbies steamed home, stringing together 20 unanswered points.

The Durban-based team retrieved a losing bonus point with replacement Ruan Pienaar's 77th-minute penalty goal, but the damage was done through their ill-discipline.

Number eight Ryan Kankowski and centre Francois Steyn left their team a man down with yellow cards at vital stages of the second half and the Sharks paid dearly as Wallaby back Adam Ashley-Cooper grabbed two tries and number eight Julian Salvi another.

The Waratahs consolidated their place in the top four with four second-half tries to claim a bonus-point win over the Lions.

The Waratahs rebounded from a dire scoreless first half in the rain with livewire scrum-half Luke Burgess sparking the home team to their fourth straight win.

The Sydney team have a crucial home game against the Coastal Sharks next Saturday.

Stormers' flyhalf Peter Grant helped his team to victory over the Hurricanes, kicking two penalties and two conversions after both teams had scored two tries.

It was a good defensive effort by the home side, who did not give the Hurricanes a chance in the first 40 minutes, but they went to sleep after the break after charging into a 20-0 lead after 55 minutes.

The Reds bounced back from a troubled season for their third victory of the campaign, scoring three tries against the bumbling try-less Force.

While the Reds have little chance of reaching the semifinals, the Perth-based Force were up until recently considered Australia's best provincial team, yet three successive defeats have them on the wane.

AFP