Goals from Theo Walcott, Santi Cazorla and Mesut Ozil put the Gunners in complete control in front 52,000 fans at a sweltering National Stadium in Singapore.
But former Chelsea keeper Cech, a virtual spectator for most of the game, was finally beaten by a spectacular effort from Ross Barkley with just 15 minutes remaining.
The Czech Republic international, who moved across London in a £10m deal last month, said: “It was great to finally have a game under my belt in what was obviously my first with the team in pre-season.
“It was important firstly to get fit and secondly to get to know everybody around me, and the main thing was to win the game. I’m obviously delighted to have played my first game, we won and we played really well.
“I’m happy with the way I played. This is the first game of the pre-season and as I said, I’m glad that I went through the 90 minutes, and I’m happy at the way I was concentrating through the whole game. The main thing for me was to win the game, to get sharp “
And Arsenal manager Arsene Wenger praised his side for the part they played in what he labelled ‘a great advert for the Premier League’.
Speaking after the match, he said: “I am pleased with this performance because the focus in pre-season is to get the quality of our game back and for long periods we played in a convincing way.
“I believe the game tonight was a great advert for the Premier League in Asia and for us it was a perfect trip because we had tremendous conditions, fantastic fans and we had two convincing games with no injuries so that’s fantastic.”