All three leading Mitre 10 Heartland Championship teams lost their unbeaten streaks on Saturday as the table has tightened up with just a five-point spread between first and eighth spot.
Having had two home games in Westport and one away match down the road in Greymouth, Buller's prospects were going to be truly tested when they left the West Coast for the first time to face Thames Valley in Paeroa.
Even with an early 1.30pm start, Buller still nearly missed their 6pm flight home after the game was delayed over an hour when local prop Hayden Anderson suffered a serious knee injury in the opening minutes, staying at the ground for around an hour before being taken away by ambulance.
In pouring rain, the teams went back into the sheds to wait, while doing drills periodically, with the home players checking in on Anderson.
Despite the disruption, Thames Valley rose to the occasion and signalled they are still a threat in 2017 with a 26-7 win, scoring two tries in each half.
James Lash could only add a conversion to Buller's sole try, falling three points back behind Steelform Wanganui's Craig Clare (64) in the season stakes.
Buller tumbled from third to seventh, although it is only differential or two competition points which separate them from five of the teams above them.
Continuing their climb was West Coast, who lowered Horowhenua Kapiti's flag for the first time this campaign with a 24-18 victory in Greymouth.
The match was delayed until 3pm due to travel delays for the visitors.
Former Wanganui halfback Kane Tamou got the starting No9 jumper he craved, but it was not a happy day for his side, who were kept in the match through goal kicking after they were outscored four tries to two.
West Coast halfback Jarrod Ferguson got a double for the home side to deliver a win to their captain Troy Tauwhare in his 50th game.
King Country's hard luck season continued as they ran out of time against North Otago in Oamaru, losing 28-26.
Taking advantage of a sinbinning in the final quarter, North Otago added another penalty and a try, with King Country closing the gap to two points with their second converted try when they were back to 15 players with four minutes left.
Don Lolo got a double for the home side, while Reece MacDonald picked up 21 points for the visitors.
Somebody was going to break their duck in Gisborne and it was home side Poverty Bay who prevailed with a 35-15 win over East Coast in their derby game.
Brody Lam scored two of the home side's five tries, which were all in the second half.
Wairarapa Bush's issues have continued and Mid Canterbury signalled an ominous warning to a hurting Wanganui after they travelled up to Masterton and smashed the home side 60-24 in the only away win of the weekend.
One test All Black Regan King scored a double, as did loan player Willie McGoon, while Maleli Sau got his fifth try of the season to remain tied with Wanganui's Timoci Seruwalu on top of the top tryscorers list.
Three second half tries did allow Wairarapa Bush to salvage a bonus point, but they have a lot of work to do to even make the Lochore Cup playoffs this season.
Results, Week 4.
Thames Valley 26 (Harry Lafituanai, Alex Bradley, Hayden Wisnewski, George Lelenoa tries; Jarrod Goodall 3 con) bt Buller 7 (Anthony Tailua try; James Lash con). HT: 14-7.
North Otago 28 (Don Lolo 2, Josh Buckham tries; Dan Lewis 3 pen, 2 con) bt King Country 26 (Alex Thrupp, Reece MacDonald tries; MacDonald 4 pen, 2 con).
Poverty Bay 35 (Brody Lam 2, Isaia Vuki, Everard Reid, Jesse Fleming tries; Andrew Tuatevalu 2 pen; Ethine Reeves 2 con) East Coast 15 (Sailosi Vatubua, Te Peehi Fairlie tries; Kris Palmer pen, con). HT: 6-5.
South Canterbury 21 (Marac Beckham, Kalavini Leatigaga, Brad Hemopo tries; Willie Wright 3 con) bt Wanganui 17 (Timoci Seruwalu try; Craig Clare 4 pen). HT: 14-7 Wanganui.
Mid Canterbury 60 (Willie McGoon 2, Regan King 2, Maleli Sau, Seta Koroitamana, Nete Caucau, Kurt Polson, Angus Lindsay tries; Jarred Percival pen, 6 con) bt Wairarapa Bush 24 (Eddie Cranston, Corey McFadzean, Epeli Rayaqayaqa, Soli Malatai tries; Tim Priest 2 con). HT: 27-7.
West Coast 24 (Jarrod Ferguson 2, Dan Food, Regan Stanton tries; Sean McClure 2 con) bt Horowhenua Kapiti 18 (W Lander, I Ecksteen tries; James So'oialo 2 pen, con). HT: 19-15.