Exeter Chiefs overcame a slow start to beat French side Castres and ensure they will play at home in the last 16 of the Heineken Champions Cup.

Castres number eight Feibyan Tukino was then dismissed before half-time for a shoulder tackle to the head.

Scores from Sam Simmonds, Jack Nowell and Christ Tshiunza, plus two penalty tries, earned a bonus point.

The first penalty try was awarded to Exeter by referee Andrew Brace during a crazy five-minute spell before half-time in which all three of Castres' back row were shown cards.

With Baptiste Delaporte and captain Mathieu Babillot sin-binned, and Tukino sent off, Castres held firm despite playing for several minutes with only 12 men.

But the visitors paid for that exertion late on when Nowell and Tshiunza touched down in the closing stages, and they will end the pool phase as the only one of the 24 teams not to take a point from their four matches.

Exeter had already confirmed their progression to the knockout phase with a game to spare but, with a home last-16 tie up for grabs, frustration grew during an error-filled opening.

They trailed to Ben Botica's early penalty until hooker Jack Innard was sent through a gap to feed England centre Slade, who was able to play after his red card against Bulls in their previous Champions Cup fixture was rescinded.

The next three Exeter tries were similar in nature, with driving mauls ending with a Simmonds try and referee Brace twice stepping in after Castres had halted them illegally.

Late scores from Nowell, who was not included in England's Six Nations squad this week, and young Wales flanker Tshiunza completed a comprehensive victory.

Line-ups

Exeter: Hodge, Nowell, Slade (c), O'Loughlin, Woodburn, Skinner, S Maunder; Kenny, Innard, Iosefa-Scott, Kirsten, Jenkins, Ewers, Tshiunza, S Simmonds.

Replacements: Frost, Sio, Williams, Dunne, Fisilau, J Maunder, J Simmonds, Kata.

Castres: Dumora, Bouzerand, Seguret, Cocagi, Larregain, Botica, Kockott; Tichit, Barlot, Chilachava, Maravat, Vanverberghe, Babillot (c), Delaporte, Tukino.

Replacements: Humbert, Tierney, Azar, Kornath, Pieterse, Ben-Nicholas, Blanc, Chabouni.

Referee: Andrew Brace (Ireland)