What to watch in the leading soccer leagues in Europe this weekend:
Chelsea has conceded on average more than two goals a game under new manager Frank Lampard this season, and the team's fragile defense will be tested this weekend by the most devastating front three in the Premier League.
Liverpool arrives at Stamford Bridge on a run of five straight wins to open the campaign, giving it a five-point lead — the biggest cushion after five games in Premier League history.
With its usually solid defense keeping only one clean sheet so far, Liverpool is relying on the free-scoring attack of Mo Salah, Sadio Mane and Roberto Firmino to maintain the team's winning streak. They have combined to score 10 of Liverpool's 15 goals so far.
Chelsea has conceded 11 goals in five league games — the same number the team has scored — with Lampard still trying to find the right balance between defense and attack. A 5-2 win at Wolverhampton Wanderers was typical of Chelsea's rather chaotic start to the season.
Looking to rebound from a surprise loss at Norwich last weekend, second-place Manchester City hosts last-place Watford, which is still without a win. Another highlight is Leicester's home match against Tottenham, with both teams in the top five.
— By Steve Douglas
Real Madrid will follow its demoralizing Champions League loss to Paris Saint-Germain with a tough trip to Spanish league leader Sevilla on Sunday.
Madrid, which trails the hosts by two points, has lost four straight league games in Seville. Its last league victory at the Ramón Sánchez-Pizjuán Stadium was in 2015.
Zinedine Zidane's team has conceded nine goals in five matches, and wasn't able to get a single shot on target in its 3-0 midweek loss at Paris Saint-Germain in the Champions League.
Unbeaten Sevilla will have newly signed forward Javier "Chicharito" Hernández facing his former club. Chicharito, who played for Madrid in 2014-15, made his Sevilla debut last week in a 1-0 win at Alavés. The game against Madrid will be only Sevilla's second at home, following a disappointing 1-1 draw against Celta Vigo.
Second-place Atlético Madrid, coming off a 2-2 home draw against Juventus in the Champions League, will try to bounce back from its league loss at Real Sociedad when it hosts Celta on Saturday.
Fifth-place Barcelona, with seven points from four league matches and coming off a 0-0 draw at Borussia Dortmund in the Champions League, visits Granada on Saturday. Lionel Messi is set to make his first league appearance of the season after missing the first four matches because of a calf injury.
— By Tales Azzoni
The Milan derby on Saturday is the highlight in Round 4 of Serie A.
Inter Milan enters with the league's only perfect record but is coming off a disappointing 1-1 draw with Slavia Prague in the Champions League.
Milan has struggled despite winning two of its three opening matches but should be fresh after not playing midweek.
Milan withdrew from this season's Europa League to avoid UEFA financial fair play penalties.
Security worries will be a concern when eight-time defending champion Juventus hosts Hellas Verona following a police operation against the Turin club's "ultra" supporters.
Napoli will attempt to build on the momentum of its Champions League victory over holder Liverpool when it visits promoted Lecce on Sunday.
— By Andrew Dampf
Buoyed by a 3-0 win over Real Madrid in the Champions League, Paris Saint-Germain goes for a fourth straight victory in the French league in an away match at Lyon.
PSG leads by two points after winning four of its opening five games.
Two of the closest pursuers, second-place Rennes and fifth-place Lille, also meet Sunday, while Marseille also seeks a fourth straight win when it hosts Montpellier on Saturday.
Schalke looks to keep up its revival under new coach David Wagner in a match against Mainz on Friday, when a win by three goals or more would be enough to lead the Bundesliga — for one night at least.
Mainz got its first win of the season last weekend against Hertha Berlin.
After dropping points against Leipzig last weekend, Bayern Munich will expect to do better at home against promoted Cologne on Saturday, when Robert Lewandowski will aim to add to his seven goals in four league games. The Bayern striker scored again in the Champions League against Red Star on Wednesday.
Bayer Leverkusen hosts promoted Union Berlin, while Hertha hosts Paderborn in a match between the league's bottom two sides. Both teams have a point from their opening four games.
League leader Leipzig can expect more protests at Werder Bremen in Saturday's late game. Leipzig is unpopular among rival fans due to its fast rise financed by an energy drinks manufacturer.
Borussia Mönchengladbach hosts Fortuna Düsseldorf before Borussia Dortmund visits Eintracht Frankfurt on Sunday.
By Ciarán Fahey