Krasny Yar sprung a huge surprise on the opening weekend of the European Challenge Cup season, claiming a bonus-point victory over defending champion Stade Francais in Siberia.

No side has successfully retained this trophy, and Stade's quest to be the first got off to a disappointing start as it went down 34-29.

The clash started positively enough for Stade, which went ahead early on through Julien Arias's try down the right. Azamat Bitiev was the man to score Krasny Yar's first European points with a score from a lineout drive, but Stade was soon 12-5 ahead as Tony Ensor went over.

Seemingly stung into action, the hosts crossed the whitewash three times in a 13-minute spell, Victor Gresev stretching over before Sione Fukofuka and Andrei Mahu breached Stade's defences.

The visitors reduced the arrears to 24-17 at the break as Terry Bouhraoua raced over and their cause was aided early in the second period as Krasny Yar's Kirill Golosnitskiy saw yellow for a deliberate knock-on.

Stade capitalised on its numerical advantage, Arias going over for his second to level matters, but Gresev matched the former France international in doubling his tally with 13 minutes to play.

Lasha Malaguradze converted that score and then kicked a penalty, meaning Karim Qadiri's try was only good enough to secure a losing bonus point for Stade, while Krasny Yar were left to celebrate a famous victory.

Elsewehere in Pool 4, Edinburgh joined Krasny Yar on five points with a 37-14 win at London Irish.

There was a first-half hat-trick for hooker Joe Taufete'e in Worcester Warriors' 30-20 win over Brive, while the other match in Pool 5 saw Connacht thrash Oyonnax 43-15.

In Pool 1, Newcastle Falcons overcame the Dragons 32-27, both sides earning bonus points.