Harvey was back in the senior coaches' chair for the first time since the end of 2011 as he oversaw the Lions' 60-point victory.
It was the first of three interim games in charge, following the mid-week axing of Michael Voss.
It is Harvey's second stint in the caretaker role after he did likewise at Fremantle following Chris Connolly's resignation late in 2007.
On that occasion Harvey won four of the final seven rounds and accepted the role as the senior coach the following year.
He held it for the next four seasons until his own sudden axing, which saw Ross Lyon's rapid and controversial entrance.
This time though, Harvey has already ruled himself out of the Lions top job in 2014, and said he was not nervous at all ahead of taking on the Giants.
He said the players' response was to be commended.
"It's been a difficult week in many ways," Harvey said.
"It's always hard to understand how the players are going to come out and react and play under those circumstances, it's very unique.
"We were happy with the way we pressured a young team, particularly early, and hit the scoreboard and reversed the mindset.
"For the rest of the game we probably controlled the tempo, which is probably a position we haven't been in a hell of a lot. From that point of view it was good."
Harvey said his primary focus over the final two rounds was to ensure the players finished the season strongly.
The Lions may have to do so without Pearce Hanley, who was subbed off during the third quarter with a hip flexor injury that will require scans this week.
Vice-captain Daniel Rich said the players tried to keep things as simple as possible following Voss' departure on Tuesday afternoon.
"It was obviously a different week, a different challenge for our group," Rich said.
"It was all about what we did in our actions tonight and the first quarter set the scene. It was a big tick for the boys. It was something different but a positive we played the way we did."
Twitter: @AFL_mikewhiting
