Arsenal thumped Bayern Munich 3-1 in a clash of the English and German league leaders on Wednesday to maintain their perfect record in the Champions League this season.

The Gunners dominated the second half after Bayern's 17-year-old midfielder Lennart Karl cancelled out Jurrien Timber's opener in the opening period.

Noni Madueke opened his goalscoring account for the Premier League frontrunners to restore their lead and fellow substitute Gabriel Martinelli took advantage of a huge blunder from goalkeeper Manuel Neuer.

England captain Harry Kane, a former Tottenham player, had a miserable return to London, largely a peripheral figure despite his astonishing goalscoring record for the six-time European champions.

"Look at Bayern Munich this season, they have been the best team in Europe," Arsenal midfielder Declan Rice said. "This was probably the toughest game tactically we have played this season. The way they work it is so, so good."

The England man said this season feels different from the previous campaign, when Arsenal again came up short, finishing second in the Premier League for a third straight season.

"There are so many leaders in the team," Rice added. "We are just taking it one game at a time. There is a hunger and desire to win every game. There is a long way to go – let's not get carried away."

Bayern started the match at the Emirates top of the Champions League table, just above the Gunners, with both teams having won four games out of four.

Meanwhile, Kylian Mbappe scored all four goals as Real Madrid hung on to beat Olympiacos 4-3 in the Champions League on Wednesday and end a three-match winless run in all competitions.

Chiquinho fired home from 20 yards to finish off a neat move as Olympiacos took an early lead in Greece, but Mbappe stole the show and took over as the competition's leading scorer this season.

"It was very important to get back to winning ways, we know that three matches without that is a lot for us," Mbappe said. "(The team) looks good to me, of course there are things to improve. At a club like Real Madrid (it's normal) that people talk."

In France, Vitinha scored a hat-trick as Paris Saint-Germain came from behind on the way to beating Tottenham Hotspur 5-3 in an action-packed Champions League clash on Wednesday.

The Portuguese playmaker cancelled out Richarlison's opener in stunning fashion just before half-time at the Parc des Princes, and repeated the trick early in the second half after Randal Kolo Muani had got Spurs' second.

The on-loan Kolo Muani had been hoping to haunt his parent club – he later scored again, but that was after the reigning European champions had punished poor Tottenham defending to net twice more themselves.

Fabian Ruiz got PSG's third and Willian Pacho their fourth, with Vitinha eventually sealing the victory from the spot as the French giants made it four wins from five in this season's Champions League.

"It is the first time in my career I have scored a hat-trick and even scored two goals in one match, so it is really special," Vitinha said.

"I'm really pleased, mainly for the victory. We came from behind twice which shows the character in the team." (AFP)