Stéphane Onambele Mbarga (Castres Olympique) - 29

The 27-year-old flanker has played all but eight minutes of Castres’ first two rounds and missed only two tackles to head up the Challenge Cup list.

That marks a fine start to Onambele Mbarga’s career with Castres after two European campaigns with RC Toulon.

Dorian Clerc (Castres Olympique) - 28

The 22-year-old Clerc has an even higher tackling success rate than his team-mate, with the lock or No.8 being beaten only once.

He made his European debut only last season, playing 50 minutes against Enisei-STM, but he has really stepped up a gear this term against Ospreys and Newcastle Falcons.

Justin Clegg (Worcester Warriors) - 28

Clegg has exactly the same tackling stats as Clerc after playing every minute of Worcester’s defeats against Pau and Ospreys.

The 23-year-old lock is slightly more experienced than the Frenchman, having made his European debut in 2018 with a three-minute appearance against Stade Français Paris.

Dan Lydiate (Ospreys) - 26

Ospreys are one of only two teams with a maximum tally of 10 points from the first two rounds – and Lydiate’s tigerish tackling is one of the reasons why.

The 33-year-old Welsh international would be even higher in the table had he not missed three tackles in the wins over Castres and Worcester.

Albert Tuisue (London Irish) - 25

London Irish boast the second-best defensive record in the competition so far this season and Tuisue has much to do with that, having been beaten only once in the tackle.

Indeed, the Fijian lock or back-row forward has proved an outstanding all-rounder for the Challenge Cup Preliminary Stage table-toppers, having also notched two tries in Irish’s opening victory over Agen.

Castres Olympique may have lost their first two matches in the 2020/21 European Rugby Challenge Cup, but they lead the way in the competition’s top tacklers so far.