The southern French outfit threw away a one-goal advantage from their first round match as four goals at home gave the Czech minnows a 4-3 aggregate victory and a place in the next round.

Coming after last weekend's shock 2-1 defeat, their first of the season, to struggling Nantes in the French league, Marseille need a win if they want to keep in touch will high-flying Lyon.

But they face a potentially tricky task at home Sunday to fifth-placed Toulouse, the only side to have taken points from Lyon this season.

Lyon stand aloft with a three-point advantage of second-placed Marseille.

And the five-time French champions will be looking to build on their winning streak by pulling further ahead of the pack by achieving their sixth win on the trot at midtable Sochaux on Saturday.

Lyon coach Gerard Houllier has warned that the best has yet to come from the champions already flying high in European and domestic league action.

Everything seems to be going their way in recent weeks.

But Houllier is convinced that his side have yet to peak.

Unbeaten in league action Lyon followed their 4-1 win over Lille last weekend by a convincing 3-0 victory at Steaua Bucharest in the Champions League Tuesday, which puts them on course to qualify from Group E.

And to underline their superiority a record eight Lyon players were selected by France coach Raymond Domenech among his 20-man squad for Euro 2008 qualifiers against Scotland and the Faroe Islands next month.

Houllier warned that his side are only beginning to click into gear.

"We won at Bordeaux (2-1), against Lille (4-1), Real Madrid (2-0) and at Bucharest (3-0) and it wasn't just luck or close calls. The team is a close-knit unit and developing all the time," said the former Liverpool boss.

Lens, Nancy and Auxerre all attack the weekend on a wave of confidence following their UEFA Cup successes.

Third-placed Lens travel to Nancy, one point behind them in fourth.

Both sides netted three goals to overcame first leg deficits in European action with Nancy advancing past German side Schalke 04, and Lens seeing off Greek side Ethnikos Achnas.

Lens have the psychological advantage however having won their last three league games while Nancy have drawn their previous three.

Midtable Auxerre, meanwhile, secured a comfortable 5-2 aggregate win over Dinamo Zagreb at home and host Nantes on Sunday.

At the other end of the table tailenders Nice travel to Lille looking to build on last week's 2-0 win at home to Valenciennes which gave them their first points of the campaign.