Mahrez's goal keeps Leicester perfect in Europe

Riyad Mahrez, had been utterly anonymous before grabbing his goal. Last season's footballer of the year, only used as a late substitute in Saturday's 3-0 loss at Chelsea, looked a passenger as his team struggled for clarity. Yet it was his typical piece of deft skill that broke the deadlock in the 40th minute.

Jamie Vardy, himself struggling for touch and involvement, crossed for Islam Slimani to head down at the opposite post. The Algerian striker nodded down for his compatriot who delicately beat Robin Olsen in Copenhagen's goal as Leicester grabbed a lead their first-half struggles looked unlikely to bring.

Even after that, they were still pretty lucky not to be level at the break, when Copenhagen striker Andreas Cornelius, found in space by Ludwig Augustinsson's cross, fizzed a header wide of the post.

On the sidelines, Ranieri's frustrations were clear from the early stages. Copenhagen, unbeaten in 23 matches since May, began far brighter, with the passing of captain Thomas Delaney particularly impressive. Copenhagen's comfort in possession might perhaps have played into a counterattacking team like Leicester's hands but Vardy and Slimani were feeding off mere slivers until the buildup to the goal.

The second half saw Leicester improve, with the outstanding Danny Drinkwater and Mahrez both going close and Slimani having a goal ruled off for offside, but tension remained high as Copenhagen pushed energetically for a late equaliser. A Federico Santander header, smuggled away for a corner by Kasper Schmeichel, had hearts in mouths. And the Denmark keeper made a truly spectacular save on 90 minutes when diving low to stop what looked a certain goal from a Cornelius shot.

Leicester hung on, and progress now looks highly likely. European football is giving them a refuge from their struggles in Premier League.

Drinkwater shines brightest for Leicester

Too many of the stars of last season have been struggling for Leicester, and despite victory, their problems were still apparent against Copenhagen.

There may be times when Vardy wonders whether he should have joined Arsenal in the summer when given the chance. He had gone seven matches without a goal before Tuesday. Rarely a man to go about his work with a smile on his face, Vardy did not look at all impressed with being asked to forge a left-side channel to feed record signing Slimani in a more central striker's position.

Slimani is clearly somebody who expects the ball to come to him, judging by a heated discussion with teammates during a first-half break in play. It is an expectation of striking contrast to the hard-working Shinji Okazaki, who creates space for the likes of Vardy and Mahrez, but who was left on the bench in favour of the Algerian. When the Japanese striker came on in the latter stages, it was for Vardy and not Slimani.

In those recent heavy defeats at Anfield, Old Trafford and Stamford Bridge, the central defensive partnership of Wes Morgan and Robert Huth has been exposed, especially on set pieces where they were once so imperious. Cornelius' free header before half-time, which had Schmeichel's dive beaten, was the kind of opportunity they just did not give up last season.

Drinkwater, meanwhile, Leicester's pass master in midfield, was being pressed hard, with Copenhagen coach Stale Solbakken repeatedly asking for him to be paid close attention.

Drinkwater took a hefty whack from a 26th minute Federico Santander challenge but soldiered on. He has been perhaps alone in playing as well this season as last, and was always at the epicentre of Leicester's best play, either when sweeping up in midfield or attempting to set up attacks.

The England midfielder was his team's outstanding player on a night where many of his teammates continued to go through the motions.

Leicester's struggle for balance

England's champions have lost four matches from eight Premier League outings, already one more than in the whole of last season's 38-game campaign. Tuesday's win meant Leicester have one more point in the Champions League than the eight they have in the Premier League. A drop-off from last season was always likely, as Ranieri had admitted in preseason, and even more so after the club was unable to prevent star midfielder N'Golo Kante from joining Chelsea.

Ranieri has so far failed in the balancing act required between domestic and European football but there is some mitigation for his team's domestic problems. The fixture list has been hugely unkind. Three of Leicester's losses have preceded Champions League matches, and each of them were daunting away trips. Next month's return trip to Copenhagen, where progress to the last 16 can definitely be secured, will follow an equally tough visit to Tottenham.

That all said, losing 4-1 at both Liverpool and Manchester United and then 3-0 at Chelsea on Saturday is unbecoming of a champion team.

There are personnel issues. Only Slimani of the summer's seven major additions started the game, saying much of transfer business that has failed to strengthen a squad that was spread thin even when delivering glory last season. At least the King Power Stadium, where Leicester are yet to lose this season, remains a stronghold. The atmosphere crackled from the start here, though not quite as frenziedly in the spring.

Perhaps once a spot in the next round of the Champions League is booked Leicester then will properly address their worrying slide in Premier League form.