The 2008 Asian champions got their AFC Champions League campaign back on track with a win over Bunyodkor, but their new boss isn't getting carried away
Matsunami was appointed last week after Jose Carlos Serrao was dismissed following a poor start to the season which saw five defeats in all competitions.
However, under Matsunami, Gamba claimed their first result of the season, with a draw at Albirex Niigata on the weekend, before Tuesday's ACL victory which came thanks to goals from Yasuhito Endo and a Rafinha brace.
The new Gamba boss, though, insisted there was plenty of work to be done despite the upturn in results.
"I am happy with my first win as manager, and this was brought by a team effort," he told reporters.
"But we are not the side to celebrate just because of one win. We will fix what we have to fix to move on to the next game.
"This victory gives us three points, which means a lot to us as our group is pretty even and competitive."
The win moves Gamba to three points in Group E, behind third-placed Bunyodkor on goal difference, while Adelaide and Pohang Steelers lead the way with six points. Gamba's next game is away to Bunyodkor.
"We will play away in Uzbekistan next and that could be a tough game for us. But we won't rest on this victory but make a step forward to play well in the AFC Champions League and the J-League," the Gamba boss added.
Meanwhile, Bunyodkor boss Mirjalol Qosimov bemoaned the defeat which he believed shouldn't have happened.
"I would like to congratulate Gamba for their win from the bottom of my heart, however, we should not have lost this game," he said.
He added: "We had good momentum, but after we gave away the first goal to Gamba, it was difficult as we were playing away.
"After the second goal, our players lost their heart and after the third one our players totally lost their commitment to the game."