Three Japanese clubs have reached the final 16 in continental competition with Dragan Stojkovic and Nelsinho Baptista's sides winning on Tuesday to clinch their places
Grampus, as well as Japanese outfit Kashiwa Reysol, progressed to the final 16 on Tuesday after favourable results, joining compatriots FC Tokyo in the knockout phase.
"After winning 3-0, I can say it was a good game and a good result for us," the Serbian told reporters.
"This is exactly what we expected, but the most important thing is that we achieved our goal in this group - qualifying for the next round."
"I think we are a better team than the Mariners, definitely, especially from the technical point of view. Our players understood well our tactical plans and it worked.
"We used a lot of space with big movement. For me, that was very important."
Grampus missed out on top spot in the group after Seongnam Ilhwa clinched a 3-0 away win at Tianjin Teda to finish first, and the Japanese now face an away trip in the Round of 16 to either Adelaide United, Pohang Steelers or Bunyodkor.
Stojkovic added: "It's a good result as we didn't lose. Of course, we expected to win against the Chinese team (Tianjin) Teda here, but we had a 0-0 draw.
"But the final result is satisfying. We played well in some games and we didn't play so good in some other games. But we played good enough to be in the first or the second place in the group."
Elsewhere, Nelsinho was rapt with his side's 2-0 away victory at Jeonbuk Motors which dumped last season's beaten finalists out of the competition.
"Jeonbuk are a tough team and we expected the counter-attack, but once we scored in the second half we had more chances and we could control the game," he said.
"The players were very confident before the game. We knew that Jeonbuk have been playing well in the K-League, but they were without their captain and we knew we had a chance."