Kaku scored early in the second half to lift Al Ain to a 2-1 victory over Wydad in the final match of the Club World Cup for both clubs.
Both teams were already eliminated from contention for the tournament's knockout round. They went into the final group match without a win in Group G, which was dominated by Juventus and Manchester City.
Manchester City defeated Juventus 5-2 simultaneously in Orlando, Florida, to claim the top spot in the group.
Wydad coach Mohamed Amine Benhachem was at the game on crutches following a traffic accident with a team physician earlier in the week. No one involved in the accident was seriously injured, but the Moroccan coach was unable to attend the team's news conference the day before the match.
Wydad scored in the fourth minute on Thursday. Cassius Mailula found himself unchallenged at the end of a cross by Mohamed Moufid and beat goalkeeper Rui PatrÃcio at the near post. Mailula is currently on loan to Wydad from Toronto FC in Major League Soccer.
Kodjo Laba converted a penalty just before halftime to pull Al Ain even.
Al Ain took the lead in the 50th minute when Paraguayan international Kaku finished into the upper right corner. Wydad centerback Jamal Harkass was injured in the run-up to the goal and had to be taken off on a stretcher.
Temperatures during the match at Audi Field were in the 90s Fahrenheit (30s Celsius).
Key moment
Laba's successful penalty, which was confirmed by video review, broke a scoreless run in the tournament by the team from the United Arab Emirates. The Togolese forward was the UAE Pro League's top scorer this past season.
Takeaways
With both teams already eliminated, the outcome was mostly a matter of pride for the winner. Wydad's only previous goal in the tournament came from Thembinkosi Lorch against Juventus.
What they said
"I think it's a good experience. It was a difficult group, with (Manchester) City and Juventus, but we competed until the end. I think this is good for Al Ain," Kaku said.
"It's been difficult, and we are sorry that we didn't get the best result. Didn't win, but learned a lot. It was a great experience for us as a team going forward, also just for us to focus and regroup, and yes, to learn. The most important thing is to learn and take lessons to grow," said Mailula.
