Barcelona lost their opening Champions League match for the first time in 23 seasons as a Thomas Muller strike and Robert Lewandowski's brace earned Bayern Munich a 3-0 win on Tuesday.

The hosts were seeking revenge following their 8-2 loss against the same opponents in the 2019-20 quarter-finals, but Bayern proved far too strong once again in the Group E opener between the two heavyweights.

Muller opened the scoring in that humbling defeat for Barca 13 months ago and did likewise in the first half at Camp Nou before Lewandowski's simple finish gave Bayern breathing space early in the second period.

Lewandowski doubled his tally late on to seal a routine win that moves the German champions into top spot after the first round of fixtures, while Barca sit bottom after Dynamo Kyiv and Benfica played out a goalless draw.

Sergi Roberto was one of six players in Barca's line-up from the memorable previous clash between the sides and the wing-back blasted over a good chance in what was a bright start from the hosts.

Bayern soon started to get to grips with the game and would have been ahead if not for Marc-Andre ter Stegen's one-handed save to keep out a powerful Leroy Sane drive.

Barca relied on some last-ditch defending to keep them level, but Muller found a way through after 34 minutes with a shot from outside the box that took a heavy deflection off Eric Garcia and left Ter Stegen wrong-footed.

Ter Stegen was again required early in the second half to keep out a low Sane shot after the winger, who had set up Muller's goal, waltzed his way through as Bayern pushed for a second.

That duly arrived after 56 minutes when Jamal Musiala's shot cannoned back off the post and Lewandowski was in the perfect position to prod the rebound into an unguarded net using the bottom of his boot.

Bayern were eager to add a third and they did so five minutes from time through Lewandowski, the prolific striker converting another rebound after Serge Gnabry this time rattled the post.

What does it mean? No revenge for Barca against rampant Bayern

Ronald Koeman described this as "a unique opportunity" for his side to exact some revenge on Bayern, but the outcome of the match was never in doubt from the moment the visitors adjusted to Barca's system around 15 minutes in.

Julian Nagelsmann's side have now won six matches in a row in all competitions, scoring 30 goals in the process, and look good value for another run deep in a competition they won as recently as 13 months ago.

As for Barca, whose last opening-game defeat in this competition was against Newcastle United in 1997-98, this one-sided affair just highlights how much work Koeman has on his hands this season.

Muller strikes again

Muller was given far too much time and space to get his shot away for the opening goal, while the less said about Garcia turning his back to the ball the better.

The Germany international has now scored seven goals in six Champions League appearances against Barca, which is more than any other player has ever managed against the Catalan giants in the European Cup or Champions League.

Shot-shy Barca

In what was the first game in their first Champions League campaign without Lionel Messi in their ranks since 2003-04, Barca's attacking players struggled to get involved in the game at all.

Koeman used a 5-3-2 formation that paired Memphis Depay and Luuk de Jong up top, but they managed just one touch in the opposition box between them in a combined 156 minutes on the field. Most damning of all, Barca did not register a single shot on target.

Key Opta Stats: Misery for Barca

- For the first time since the start of Opta Champions League data (2003-04 onwards), Barcelona have failed to get a shot on target in a match (this was their 186th game in the competition during that timeframe).
- Barcelona have suffered eight defeats to Bayern in major European competitions, twice as many as they have against any other club. 
- Barca have also shipped at least three goals in five of their last six games against Bayern (21 goals in total).
- This defeat means Barca have lost three consecutive home games in European competition for the first time in their entire history.
- Barcelona have suffered three home UCL defeats by 3+ goals since the start of last season (0-3 vs Juventus, 1-4 vs PSG, 0-3 v Bayern), one more than in their first 24 UCL campaigns combined.

What's next?

Barcelona belatedly return to LaLiga action next Monday with a home match against Granada. Bayern host Bochum in the Bundesliga on Saturday.