The Black Star restored the home side's lead after Cheick Diabate cancelled Mickael Ciani's opener at the Stade du Moustoir.
Jimmy Cabot then netted twice before Benjamin Moukandjo fetched the last goal on 78 minutes.
"I was excited to get on the scoresheet, but the most important thing was that the team got a very important win, so I am very happy," Waris told BBC Sport.
"The players gave everything on the pitch and we got our rewards. We deserved it and it was a fantastic performance.
"We are happy with this win and we need to win more games now because the important thing this season is that we stay in Ligue 1."
By the win, Lorient have moved out of the danger zone, but not far off as only two points separate them and relegation-trapped Dijon.
"If we continue working hard for the rest of the season I believe we'll win games away and at home," Waris said.
"We have players with strong mental ability and the will to survive, so we have to make the most of that.
"The atmosphere in the changing room after the game against Metz was fantastic. Hopefully it's the start of many more here."
Waris has so far made 31 league appearances involving 27 starts for Lorient this season.
The 25-year-old has notched nine goals in addition to five assists.