Newcastle, Exeter, London Irish, Cardiff and Connacht recorded bonus-point wins in the Challenge Cup.
France full-back Scott Spedding will leave Bayonne to play for Clermont next season.
Jake White's first game in charge of Montpellier ended in a win over Toulon, while Stade Francais hung on to top spot.
Stade Francais shocked defending champions Toulon 30-6 to end the year at the summit of the Top 14.
Wins for Toulon and Clermont at the weekend has kept the race for top spot alive in France's Top 14.
Round Four of the European Rugby Challenge Cup continues on Saturday, with six fixtures on the cards.
Wins for Cardiff Blues, Connacht and Newport Gwent Dragons in round three of the European Challenge Cup.
Saturday's European Rugby Challenge Cup billing sees four matches, with London Irish and Connacht both in action.
Reigning Top 14 champions Toulon claimed a 27-19 victory against Clermont Auvergne in a clash of the titans on Saturday.
A depleted Toulon team came a cropper at Castres, allowing Clermont Auvergne to take over as new leaders in the Top 14.
The final of the Top 14 will be held at Barcelona’s Nou Camp at the end of the 2015-16 season.
Scott Spedding has been called up by France for their November Tests against Fiji, Australia and Argentina.
Oyannax caused the biggest upset of the Top 14 season so far on Saturday by clinching victory away at Racing Metro.
London Irish made it two wins from two in the Challenge Cup as they battled past Grenoble 25-15 in France.
Friday sees five games in Round 2 of the newly-formed European Rugby Challenge Cup, including Dragons against Newcastle.
Cardiff Blues kicked off their European Rugby Challenge Cup campaign with a 37-14 bonus-point victory over Grenoble.
There are seven European Rugby Challenge Cup matches across Saturday and Sunday. Sky Sports previews them all.
Corey Flynn was sent off as Bayonne’s 35-19 home success condemned Toulouse to a fifth straight defeat in the Top 14.
Guy Noves insists he is not worried by Toulouse's slump in form heading into Friday's Top 14 clash with Bayonne.
Clermont returned to the summit of the Top 14 standings in style while Castres climbed out of the relegation zone.
Rupert Cox shares his highlights from the week's rugby action in his round-up blog.