Toulon will have to get past the hefty obstacle of a Dan Carter-inspired Racing 92 team in quarter-final action this weekend in their bid to nail down an unprecedented fourth consecutive European Cup title.

The star-studded Toulon side, with World Player of the Year Carter's long-time All Black teammate Ma'a Nonu at centre, landed an early blow over their last-four rivals in the Top 14 two weeks ago, a late Frederic Michalak penalty enough to snatch a 21-20 win.

"Toulon are reigning European champions and have experienced players," said Racing hooker Dimitri Szarzewski.

"We know what to expect -- a big physical challenge against players capable of making the difference. We have to play the perfect match."

History is certainly on Toulon's side come Sunday's game in Paris, the Mourad Boudjellal-financed club having won all of their last nine knockout matches in the Champions Cup.

Their only loss came in their first quarter-final against Perpignan in 2011.

But with Carter pulling the strings behind a powerful pack, Racing have the capability to dethrone the champions.

In all, four mouth-watering fixtures will be played out on Saturday and Sunday, an all Anglo-French affair with five teams from the Premiership and the three from the Top 14.

Aside from Toulon's trio of titles, three of the remaining English clubs won five titles in eight heady seasons, albeit between 2000-07 -- Northampton (2000), Leicester (2001, 2002), Wasps (2004, 2007).

English champions Saracens were beaten by Toulon in the 2014 final and lost out to Clermont in last season's semi-final.

But Saracens have been Europe's form side this season, claiming six pool wins from six to advance as top seeds and a match against domestic rivals Northampton.

"We have gone close in Europe over the last couple of seasons but we have not been able to get our hands on the trophy, which is what everyone wants to do," said Saracens flanker Jackson Wray.

"We obviously did well in the pool stage, we were really happy with how that part of the competition went and the competitiveness of the Premiership means we are confident of hitting that level again."

Saracens welcome back the likes of Owen Farrell, Maro Itoje and Billy Vunipola, who were all vital parts of England's Grand Slam-winning Six Nations squad.

"The guys have come back and, as you would expect, they are buzzing and that enthusiasm and confidence rubs off on other guys," said Wray.

Wasps take on Exeter in what could be a classic of running rugby.

Wasps racked up big pool victories over Leinster (51-10 and 33-6), reigning champions Toulon (32-6) and Bath (36-10), and Exeter coach Rob Baxter admitted he was wary of their attacking game.

"The best way to nullify Wasps' attack isn't to defend it. The best way is to attack it yourself, to have the ball," Baxter said.

"I think we have got to make sure we remember that. If we are attacking, they haven't got the ball, and that is a pretty good form of defence. That's the approach I want us to have."

On paper, the easiest of task seems to be Leicester's, at home against Stade Francais.

The French champions have suffered a disastrous domestic campaign in their Top 14 title defence and sit only one place above the relegation places with realistically no hope of making the end of season play-offs.

"We'll go there with no complex, with a lot of enthusiasm because it's our only knock-out phase," Stade's Italy captain and No 8 Sergio Parisse said.

Fixtures (all times GMT)

Saturday

Wasps (ENG) v Exeter (ENG) (1315)

Saracens (ENG) v Northampton (ENG) (1545)

Sunday

Leicester (ENG) v Stade Francais (FRA) (1145)

Racing 92 (FRA) v Toulon (FRA) (1415)
Source: AFP