Alexis Sanchez salvaged a point for Arsenal in their hotly contested Champions League opener against French Champions PSG in Paris.

Striker Edinson Cavani glanced PSG ahead after 42 seconds and should have had a hat-trick before half-time, firing wide after rounding David Ospina before slipping to fluff a simple finish.

Sanchez rifled in Arsenal's first shot on target with 13 minutes left to equalise an Alex Iwobi might have had a late winner before Arsenal's Olivier Giroud and PSG's Marco Verratti were sent off for an off-the-ball altercation.

Arsenal's Chilean forward Alexis Sanchez (R) shoots during the UEFA Champions League Group A football match between Paris-Saint-Germain vs Arsenal FC, on September 13, 2016 at the Parc des Princes stadium in Paris.  / AFP / MIGUEL MEDINA        (Photo credit should read MIGUEL MEDINA/AFP/Getty Images)
Arsenal's Chilean forward Alexis Sanchez (R) shoots during the UEFA Champions League Group A football match between Paris-Saint-Germain vs Arsenal FC, on September 13, 2016 at the Parc des Princes stadium in Paris. MIGUEL MEDINA/AFP/Getty Images.

In Holland, PSV were out for revenge against last season's runners-up Atletico Madrid, who knocked them out on penalties in the Round of 16.

The home side was denied a penalty shout early in the first half and had the better run of play before Atletico midfielder Saul, famous for scoring that cracker against Bayern Munich in the semi-final last season, produced another moment of magic, volleying in a left-footed finish to putย Atleti up 1-0.

The Spanish giants went on to close out the match to take home a gutsy three points in enemy territory.

Lionel Messi scored his sixth Champions League hat-trick as aย rampant Barcelona inflicted a 7-0 thumping on Celtic at the Nou Camp,ย their heaviest ever European defeat.

The Argentine forward cracked in an early first goal in the Group C match before Celtic's Moussa Dembele had a penalty savedย leading Messi to scoreย his second in the half.

In the second half, Neymar's crackingย free-kick sailed into the net, Andres Iniesta volleyed a fourth, Messi slid home the fifth and Suarez scored with a volley and then a side-footed finish to complete the resounding performance.
Full Results
PSV 0 Atletico Madrid 1 (Saul 43')
Basel (Steffen 80') 1 Ludogorets Razgrad 1 (Cafu 45')
Benfica (Cervi 12') 1 Besiktas 1 (Talisca 93')
Barcelona (Messi 3', 27' & 60', Neymar 50', Iniesta 59', Suarez 75' & 88') 7 Celtic 0
FC Bayern Munich (Lewandowski 28', Muller 47', Kimmich 53' & 60', Bernat 90') 5 FC Rostov 0
PSG (Cavani 1') 1 Arsenal 1ย (Sanchez 77')
Dynamo Kyiv (Garmash 26') 1 Napoli 2 (Milik 36' & 47')
Manchester City vs Borussia Monchengladbach - Postponed tomorrow morning
Tomorrow Morning (All games kick-off at 4:45am AEST)
Club Brugge vs Leicester City
Tottenham Hotspur vs Monaco
Legia Warsaw vs Borussia Dortmund
FC Porto vs FC Kobenhavn
Lyon vs Dinamo Zagreb
Juventus vs Sevilla
Bayer Leverkusen vs CSKA Moscow
Real Madrid vs Sporting Lisbon
Manchester City vs Borussia Monchengladbach