UCL: Guardiola's much-changed Man City lose to Leverkusen, Chelsea beat 10-man Barcelona

On a night of changes, miscues and a spirited goal by 18-year-old striker Estevao, defensive lapses cost Manchester City and Barcelona dearly as both teams slumped to unwanted setbacks in the UEFA Champions League on Tuesday.

In Pep Guardiola's 100th Champions League match as City's manager, his team struggled to cope with Bayer Leverkusen's quick transitions in a 2-0 home defeat, while Barcelona endured an own goal and red card in a 3-0 loss at Chelsea.

Guardiola made 10 changes to his starting lineup following Saturday's loss to Newcastle in the English Premier League, with star forward Erling Haaland among those on the bench, but the rearrangements did not have the desired effect.

Alejandro Grimaldo fired home Leverkusen's first goal with a low shot into the far corner in the 23rd minute, before Patrik Schick headed in a second in the 54th.

"It feels wonderful and we gave everything 'til the last second," Schick said after the match.

Chelsea comfortably beat 10-man Barcelona 3-0 at Stamford Bridge to earn their third league-phase win, moving closer to the top of the standings.

The loss was the second for Barcelona, which went down a man after defender Ronald Araujo was shown a second yellow card just before halftime, following a forceful tackle on Marc Cucurella.

Jules Kounde's own goal gifted Chelsea the lead in the 27th minute, with Barca's defenders getting tangled up in front of the net.

The hosts extended their edge with a fine individual goal by Estevao in the 55th as he held off two defenders, followed by a close-range shot from Liam Delap in the 73rd.

Barcelona's fourth defeat in 10 games in all competitions could invite more criticism of coach Hansi Flick's approach.

City would have moved into first place with a victory, but the night ended with the top three unchanged. Bayern Munich, Arsenal and Inter Milan will all play on Wednesday.

Borussia Dortmund rose to fourth and Chelsea sit fifth after both sides won, joining City with 10 points. Barca dropped to 15th while Juventus improved to 21st after edging Bodo/Glimt, as the Italian club try to turn around their campaign.

While Guardiola suffered an unexpected loss, old rival Jose Mourinho picked up his first Champions League victory with Benfica, as defender Samuel Dahl's early goal set the stage for a 2-0 win over troubled Ajax. It was No. 36 vs. No. 35 in the pre-game standings, as two winless teams met in Amsterdam.

Dahl scored an unstoppable volley in the sixth minute and Leandro Barreiro added a second goal for the Portuguese club in the 90th. Ajax have lost all five of their Champions League matches, with the Dutch side earning just one win in their last 10 contests in all competitions.