The Stormers had to scramble to maintain their unbeaten start to Super Rugby against the struggling Sunwolves on Saturday while the Blues and Highlanders completed another convincing weekend for New Zealand teams.
South Africa's Stormers trailed 24-10 to the Sunwolves in Singapore - where they only drew last season - before taking control through their superior forward pack to grind out a 44-31 win.
The Stormers, with a 4-0 record, are one of three teams still unbeaten. The Crusaders (5-0) overpowered the Western Force on Friday to take over the lead overall from New Zealand rivals the Chiefs, also unbeaten but who had a bye weekend.
Defending champions the Hurricanes (3-1) also had a bye.
Along with the Stormers' fightback, the Blues overwhelmed the Bulls 38-14, and the Highlanders scored a late try, and defended desperately right at the end, to beat the ACT Brumbies 18-13.
The Blues and Highlanders victories meant success for all three New Zealand teams in action in this round.
In South Africa, the Lions romped past the Southern Kings 42-19 and the Sharks edged past the Cheetahs 38-30.
In Argentina, the Jaguares beat the Queensland Reds for the first time, 22-8.
The conference leaders and top four in the overall standings are: The Christchurch-based Crusaders, Johannesburg-based Lions, Cape Town-based Stormers, and Canberra-based Brumbies. But, three of the other four playoff places are occupied by outfits from New Zealand.
The Jaguares, now a tough challenge for anyone in their second season in Super Rugby, could go second overall by the end of the round.
With the Stormers floundering, the Sunwolves were 14 points ahead in the first half with tries by Derek Carpenter, Shota Emi, and Liaki Moli. Center Carpenter ended up with two.
Ultimately, the South African team outscored the Japan-based Sunwolves six tries to four after it went back to basics and its pack and halfbacks wrenched control of the game in the second half.
''We had to fight for it,'' Stormers captain Siya Kolisi said. ''We really respect these guys. They're getting better and better.''
Earlier, winger Matt Duffie scored two of five second-half tries for the Auckland-based Blues to beat South Africa's Bulls.
Duffie touched down twice within 10 minutes at the start of the second half as the Blues overcame a disorganized first-half performance, which left the scores tied 7-7 at halftime, to win by six tries to two.
The match at Eden Park snapped the Blues' three-match losing streak, with those losses all to New Zealand opposition. It went much better for the Blues against the Pretoria-based Bulls.
The game turned in the Blues' favor in the second half when they lost their structure. Without the need to build from set-pieces but instead to create play from Bulls' turnovers, the Blues were far more effective and scored five tries after halftime.
The Highlanders snatched victory at the Brumbies when prop Aki Seiuli powered over between the posts with seven minutes to go, although the 2015 champions are bottom of the New Zealand conference.
The Lions put in a scintillating first-half display and coasted home for an easy win over the Kings, with 19-year-old Congolese-born winger Madosh Tambwe, a highly rated prospect, scoring two tries in his second Super Rugby game.
The Sharks retained their place in the top eight by beating the Cheetahs in their South African derby, with flyhalf Curwin Bosch, another teenage talent, contributing 18 points in his latest impressive showing.
The Jaguares bagged their third straight home win at Queensland's expense.
Center Jeronimo de la Fuenta and winger Ramiro Moyano scored tries as the Jaguares exploited an eight-minute spell in the first half in which Queensland winger Eto Nabuli and lock Kane Douglas were in the sin-bin, reducing them to 13 men.
The Jaguares led 15-8 at halftime and sealed their win with de la Fuente's second try during a scrappy second half.
