Radamel Falcao's brace along with Emmanuel Riviere's strike mean the newly promoted side remain unbeaten on top of the French league, ahead of reigning champions Paris Saint-Germain.
The Italian tactician was pleased with the performance against Bastia; a side that he rates quite highly.
"(Bastia's) four players in attack were very good and they also have a good defence with experience so I am very happy with the game because I think that in the end, both teams played a good game," Ranieri said on Wednesday.
"It was a great game because both teams had a lot of chances and both goalkeepers had to make some great saves."
Ranieri said he is focusing on building a team and admits there are still plenty of areas his side can work on.
Monaco have spent plenty of money since they were promoted to Ligue 1 at the end of last season, bringing in Falcao (€60million), James Rodriguez (€45m) and Joao Moutinho (€25m) all joining the principality club.
Ranieri remains convinced Monaco can improve as the likes of Falcao, Rodriguez and Moutinho continue to gel with their new teammates such as Riviere, Geoffrey Kondogbia and Lucas Ocampos.
"It was good without thinking about being in first position in the table and it is important to us to build our game," the 61-year-old coach said.
"The most important thing for us is to build a team because the first 20-25 minutes, we were not playing smoothly."
Monaco travel to Reims on Sunday as they look to extend their unbeaten Ligue 1 run to eight games.
