Champion Olympiakos travels to AEK Athens as the new season kicks off this weekend with its rivals desperate to break the Piraeus club's dominance after its fifth straight title and 12th in 13 years. Olympiakos already looks set for a place in the Champions League's group stage after an easy 2-0 win on Tuesday against Moldovan side Sheriff. Former Newcastle United player Temuri Ketsbaia, who took over as Olympiakos manager in the offseason, has bolstered the team's defense by signing Swedish international Olof Mellberg on a three-year contract from Juventus but has made no other major acquisitions. 'We're always looking for (new) players. But I'm the coach, and I have to work with the players we have. We have to be ready to face AEK,' Ketsbaia said. In contrast, archrival Panathinaikos has made a number of high profile signings, including 29-year-old French striker Djibril Cisse from Marseille on a four-year contract worth more than euro20 million (US$28.5 million). It has also snapped up Sebastian Leto from Liverpool after he spent last season in Greece on loan to Olympiakos. The Athens club lost its opening European game Wednesday, 3-2 at home to Atletico Madrid, and looks unlikely to progress further in the Champions League. This weekend, Panathinaikos faces lowly Ergotelis, and Dutch coach Henk Ten Cate said he's looking to get off to a good start, with the league his top priority. 'The league is our number one target. Everyone knows that,' Ten Cate said. 'I saw a lot of positive things in the (Atletico) game -- things we can build on. So I'm optimistic about the (Greek) championship.' AEK and PAOK Thessaloniki face action in the Europa League playoffs. But the Athens club has already suffered a serious setback to its domestic title hopes, losing central defender Sotiris Kyrgiakos to Liverpool. The 16-team, 30-round league will last through April 18, 2010 and will include breaks for World Cup qualifiers. After 28 years in the lower divisions, Kavala returns to Greece's top flight. Giannina, another provincial club, has also returned after a 10-year absence, along with Atromitos which spent last season in the second division. In other first-round games this weekend it's: Aris vs.Atromitos, Xanthi vs.Giannina, Asteras vs.Larissa, Levadiakos vs.Kavala, Panthrakikos vs.Iraklis, and Panionios vs.PAOK. 