"Great job everyone, what a weekend," said Hamilton on the team radio immediately after winning at the Marina Bay Street Circuit for the second consecutive year. "Keep pushing. We've got this guys," he added.
Challenges such as the track configuration as well as the heat and humidity of Singapore's tropical climate make the Grand Prix the toughest physical test of the season.
The 5.063 kilometre circuit sports 23 bends and needs around 80 gear changes on each of the 61 laps. "I'm spent. It felt like the longest race of my life so I'm glad it's over,” said Hamilton.
Valtteri Bottas in the second Mercedes came fourth while Kimi Raikkonen in the other Ferrari finished fifth.
The next Grand Prix of the season takes place in Russia on 30 September. That is followed by races in Japan, the United States, Mexico and Brazil. The 2018 campaign culminates on 25 November in Abu Dhabi.