Paris St Germain wasted the chance to ignite their stuttering start to the season when they were held to a 1-1 home draw by Arsenal in their Champions League Group A opener on Tuesday.

The hosts enjoyed a dream start when Edinson Cavani put them ahead in the first minute but PSG squandered numerous opportunities and paid dearly when Alexis Sanchez swept in an equaliser late in the second half.

Cavani headed home after just 44 seconds but PSG gradually let Arsenal fight their way back into the game until Sanchez fired home from just inside the box in the 78th minute.

Both sides ended with 10 men after Arsenal's Olivier Giroud and PSG's Marco Verratti were shown red cards for an innocuous off-the-ball incident in stoppage time.

French champions PSG, who took only one point from their last two Ligue 1 games, next travel to Ludogorets while Arsenal will host Basel on Sept. 28. Basel and Ludogorets also drew 1-1.

"For a home game we would have preferred all three points especially since we played much better. We wasted chances but we played a good game," said PSG's Blaise Matuidi.

PSG were boosted by the return of centre back Thiago Silva who made his first appearance of the season after a hip injury.

Grzegorz Krychowiak started in midfield alongside Adrien Rabiot and Marco Verratti while Blaise Matuidi was fielded in an unusual position on the left wing to contain Hector Bellerin.

For Arsenal, Giroud started on the bench with Sanchez up front and Alex Iwobi on the right wing.

Cavani benefited from some loosing marking by the Arsenal centre backs to glance home Serge Aurier's cross.

Angel Di Maria proved a constant threat, finding Rabiot in the box with a superb backheel and forcing Arsenal keeper David Ospina to a spectacular save direct from a corner.

Cavani missed a sitter in the 35th minute, shooting wide in front of an empty goal after going around Ospina.

LACKED PRESENCE

Arsenal relied mainly on counter-attacking but started the second half by applying some pressure but lacked presence in the box with their fans chanting Giroud's name.

The France striker came on for Alex Oxlade-Chamberlain in the 63rd minute as Sanchez went to the left wing.

PSG had two more clear chances in the 67th and 69th minutes through Aurier and Cavani.

The home side paid for their failure to kill off the game when Arsenal equalised in the 78th minute.

Alphonse Areola made a great save to deny Iwobi but the ball rebounded out and Sanchez was lurking to fire home.

Shortly afterwards Cavani missed another great chance when he failed to go around Ospina after collecting a through ball in the box, the keeper sticking out an arm to claw the ball away.

Iwobi came close to winning it for Arsenal in the 83rd but Areola stretched to his left to tip the ball away to save new coach Unai Emery's blushes on his PSG Champions League debut.

"I think it's a good point but we came here with our ambition and we wanted to have the three," Arsenal defender Laurent Koscielny said.

"But when we start like this it's difficult to play."