PSG rounded off a fine Champions League Group A campaign with a 5-0 thrashing of sorry Galatasaray at the Parc des Princes on Wednesday.
Brazil superstar Neymar was the star of the show, setting up two goals and scoring one himself.
Neymar could well have doubled his tally late on, after Kylian Mbappe – who netted PSG's fourth goal – was brought down by Ryan Donk in the area.
The former Barcelona forward instead handed the ball to Cavani, who made no mistake as he sent fellow Uruguayan Fernando Muslera the wrong way to score his first club goal since August.
Cavani and Neymar infamously squabbled over a spot-kick in a match against Lyon shortly after the latter's arrival in Paris in 2017, with PSG's record goalscorer eventually pulling rank, only to miss. However, the team-mates certainly proved any disagreement was far behind them.
"It was a nice gesture," Tuchel told a news conference.
"Everyone can see, Ney is very sensitive. He gave the ball to Edi and it's a good symbol for the team.
"Neymar was already super important and very good at Montpellier [a 3-1 win on Saturday]. He was decisive for us and he's getting better.
"He worked hard today, won lots of balls and did well defensively. He's finding his form. It's easier for him now.
"Cavani lacked rhythm and that was my fault and the fault of injuries. It was important for him to score. It's the best way to get confidence and I'm very happy for him."
PSG finished top of Group A with 16 points, five more than second-place Real Madrid, who they dismantled 3-0 on matchday one.
The Ligue 1 champions – who were defeated by Manchester United in the last 16 in 2018-19 – will find out their opponents for the first knockout round in Monday's draw.