Super Rugby’s paupers – the Western Force and Lions – turned to kings while the Sharks, Chiefs and Reds all lost their sheen in a controversial round of upsets.

The underdog Western Force have turned Super Rugby on its head with the biggest upset win of a controversial weekend littered with them.

Last year’s Australian conference wooden-spooners, the Force ended a six-match winning streak by the defending champion Chiefs with a spirited 18-15 victory in Perth on Saturday night.

Built on a gutsy defence that kept the Chiefs tryless on Australian soil for the first time in 13 years, the triumph gave the battling WA franchise their first three-match roll of success since 2007.

It has the Force, written off as “the worst team in the competition” three weeks ago by former Wallaby Greg Martin following limp losses to the Waratahs and the Brumbies, realistically eying an unlikely finals shot.

Captain courageous Matt Hodgson scored the only two tries of the match, while his team squeezed the normally composed Kiwis with a relentless pressure game perfectly implemented from 1 to 15.

Dave Rennie, who has guided the Chiefs to the last two championships, praised the character of the Force but warned their biggest challenge is winning enough local derbies.

“They’re in a pretty tough conference aren’t they?” Rennie said. “You’ve got a very good Waratahs side. The Brumbies are a good team. They’ve got the Reds.

“To get through, they’re going to have to win those derbies. They’re key games.”

That challenge will come immediately after next week’s bye, when they take on a Queensland side left seething by a 17-4 penalty count against them by South African referee Stuart Berry that was key to their 23-20 loss to Super Rugby’s comeback kids – the Lions.

Like the Force, the Johannesburg-based Lions – who made up a 17-point deficit on Sunday morning – were expected to merely make up the numbers in 2014 but now have four upsets from six matches.

Berry wasn’t the only whistle-blower heavily criticised for questionable decisions over the weekend, as Cheetahs coach Naka Drotske demanded an explanation from SANZAR following two contentious rulings by Argentine referee Francisco Pastrana in their 40-30 loss to the Blues in Auckland.

The 10th-placed Reds (2-3) must now return home and put their season back on track against a Stormers side under even more pressure after losing 25-15 to the injury-hit Brumbies in Canberra.

Stormers coach Allister Coetzee rated the Brumbies scrum among the best in the competition as they sealed a gritty victory with a final-minute penalty try.

The win keeps the second-placed ACT outfit at the top of the Australian conference with 17 points, one clear of the Waratahs, who have a game in hand.

Coming off a 32-8 victory over the Melbourne Rebels, NSW can put their stamp on the competition next weekend against the table-topping Sharks (19) in Durban.

The Sharks were the last side left unbeaten before their archrivals, the Bulls, produced a dominant second-half in Pretoria to surprise them 23-19.

Hurricanes coach Mark Hammett is under the gun in Wellington after his side fell 35-31 to the Highlanders in Dunedin.