Bok flyhalf helps Stade end losing run
Lyon stormed back into the play-off picture with a shock 27-20 victory at fourth-placed Toulouse.
Australian lock Hugh Pyle and Fijian wing Waisea Nayacalevu scored tries as Stade eased clear of the drop zone with their first win in six matches.
Stade had started the weekend just a point above the relegation zone but this victory took them up one place to 11th and opened a five-point gap to second from bottom Brive.
The victory came after successive defeats to relegation rivals Oyonnax and Agen.
"Against Agen and Oyonnax we lost because we were clearly lacking in confidence," said Stade's back-row forward Antoine Burban.
"Here, we managed to hang on right to the end."
Castres crossed the whitewash twice through Tongan flank Maama Vaipulu and South African-born France international scrumhalf Rory Kockott but flyhalf Benjamin Urdapilleta could not match Steyn's output with the boot.
Steyn kicked two conversions, two penalties and a drop goal.
Pyle opened the scoring in the corner on 13 minutes after a remarkable no-look tap-pass over his own head from Waisea.
Forward power came to the fore as Vaipulu replied for Castres but Steyn landed a penalty and a drop goal early in the second period to give Stade a six-point advantage.
After Waisea finished off a sweeping move to extend the lead, Kockott pounced on a loose ball to score as sloppy handling from both sides created chaos on Stade's line.
But with 12 minutes left to try to snatch something from the match, Castres still came up empty-handed.
Former England fullback Delon Armitage scored two tries with New Zealander wing Toby Arnold chipping in with another as a late Lyon rally turned their game on its head.
Yoann Huget and Cyril Baille scored tries as Toulouse opened up a 14-3 lead at half-time.
But from the moment Arnold crossed the whitewash on the hour, Lyon dominated.
"We put in maybe our worst first half of the season but we managed to rebel and that's important for the rest of the season," said Arnold.
"We're in the [top] six and we all want to stay there."
Armitage's first try gave Lyon the lead for the first time but after two Thomas Ramos penalties they found themselves 20-17 behind with five minutes left.
A penalty from Australian fly-half Mike Harris levelled the scores before Armitage's try three minutes from the end won it and moved Lyon up to sixth.
On Saturday, Montpellier extended their lead by steamrollering second-placed Racing 92 41-3.
But the game was most notable for a pre-match flare-up between Montpellier's front row pair Bismarck Du Plessis and Mohamed Haouas that saw them exchange punches before being dragged apart by teammates.
Champions Clermont won away from home for the first time this season with a narrow 11-9 success at Brive that saw them climb one place to ninth, although still some 12 points off a play-off spot.
Veteran wing Vincent Clerc equalled the record of 100 French top-flight tries as Toulon thumped Agen 54-5.
Bottom side Oyonnax continued their stunning revival with a third straight victory, 26-20 at free-falling Bordeaux, to bring them to just five points from safety.
Before this run they had won just once in 17 matches and had seemed relegation certainties.
Agence France-Presse
