The Crusaders clinched a home Super 14 playoff place but the identity of the other three semifinalists was still to be determined after a weekend of thrilling finishes.

The six-time champion Crusaders opened up a 10-point lead at the top of the southern hemisphere provincial championship standings with two games left after grafting an 18-10 win over the Sharks in Christchurch on Friday.

The Durban team's third straight loss pushed them out of the top four to sixth but they have two home games left to force their way back into the playoffs.

Scoring opportunities were at a premium in the weekend's feature match in heavy rain and a try to Crusaders replacement prop Wyatt Crockett in the 74th minute secured victory over the Sharks.

The Waratahs clung on to second spot but only after prising a bonus point out of their 16-13 loss to the Bulls in Pretoria on Saturday, with last year's champions getting home on the back of two drop goals.

It was a seesaw affair in miserable wet conditions, with try-scoring chances limited.

Both sides crossed the tryline just once, with the Bulls edging the Waratahs thanks to drop goals by Derick Hougaard and Morne Steyn.

The Sydney team, on 37 points, are just ahead of the Hurricanes in third place on 36 points after the Hurricanes comfortably held off the struggling Lions 38-12 at home on Saturday.

The Wellington team were not at their best in their first game back home after their South African tour but for the most part they were far too good for the Lions, who remain firmly entrenched at the bottom of the table.

The Stormers complete the top four after all but extinguishing the ACT Brumbies' semifinal hopes with a 20-10 triumph in Cape Town on Saturday.

The Stormers buried their Brumbies hoodoo with 20 points in a 17-minute mid-first half scoring blitz and were never in serious danger of losing.

The Chiefs had a setback going down 22-21 to a last-minute penalty to the Western Force in Perth and eased to fifth place on 33 points.

A Jeff Bruce drop goal in the 76th minute had appeared to secure a crucial win for the Chiefs, only for Matt Giteau's penalty to snatch a victory that had looked the Force's for much of the night until a late surge by the visitors.

The Sharks are next on 32 points, just ahead of the seventh-placed Blues, who remained in playoff contention with a bonus-point try in the final minute in their 35-22 win over the Reds in Brisbane on Friday.

Scrumhalf Taniela Moa scored The Blues’ fourth try to come away with a maximum five points against Queensland to still have control of their playoff destiny.

The Blues need to win their remaining matches away to the Highlanders next week and at home to the Hurricanes to play in the semifinals.

In the remaining match the Highlanders scored just their second win of the year in defeating the Cheetahs 31-28 in Bloemfontein.

AFP