I've been told it was an orange card [for Pedro], and it seems to be that when we play here things go the other way if it's a 50-50 decision.
"We want to be united and together throughout the season." said Arsene Wenger after the match.
With no extra-time, penalties ensued and for some reason, Conte selected Courtois to take their second effort: the gamble didn't work as he blazed his effort over.
But Chelsea goalkeeper Thibaut Courtois blazed his kick over the crossbar followed by striker Alvaro Morata also missing.
Chelsea had Pedro dismissed for an untidy lunge on Mohamed Elneny 82 seconds before Kolasinac converted Granit Xhaka's cross, but Wenger felt an Arsenal leveller had always been on the cards, irrespective of any numerical advantage.
Arsenal's win against Chelsea capped what has been a promising pre-season for the club as they beat Bayern Munich, also on penalties, as well as lifting the Emirates Cup.
Seaman's former teammate Paul Merson is not so optimistic about Arsenal's league prospects this season.
Kolasinac, signed on a free transfer from Schalke, started Sunday's Community Shield on the substitutes' bench, but had to come on for his debut earlier than expected when Per Mertesacker suffered a first-half head injury.
"For sure, there is disappointment to finish for the second time with 10 men against Arsenal", Conte said, quoted by the Telegraph.
Alex Oxlade-Chamberlain then scored for Wenger's men before Olivier Giroud wrapped up the win. He was slower to pass and slower to defend and move around, he was even grimacing as Kolasinac's goal went in.
"In the Premier League the power plays a part but it is not only that".
Conte has spoken out several times over his frustrations about the size of Chelsea's squad and - despite adding Antonio Rudiger and Tiemoue Bakayoko as well as Morata - Cahill shared those concerns.
"We have had some bad starts recently in the last four years in the first game of the Premier League".