Dzeko struck in the 4-2 victory.
Fonseca said, “I spoke to Edin Dzeko a great deal during pre-season. He is a very important player. He scored a goal today, could've had more, but he is an excellent forward.
“We changed a few things this evening. Pellegrini played as a trequartista. With Jordan Veretout and Mkhitaryan, we've got a better capacity for maintaining possession. Everyone played well today.
“I tell everyone to press high and that is an important element. It worked well this evening. That does mean running some risks, but the high press is important and, when done well, actually gives you fewer risks in defence."