The German started on medium tyres as opposed to the rest of the field on super-soft - a strategy which allowed him to lead the race for a few laps.
He said: "What a fantastic race and a great feeling.
"I started on the medium tyres, a different strategy to most of the cars ahead of me, and I think this was the right decision. The pace was quick and the car felt very good on the medium tyres so I was able to keep up with the guys in front of me, who I knew were going to pit early.
"It was not long until I was leading the race - my first time leading in Formula One. After my second pit stop I was back in the lead once again, so I knew that it was possible to come away with a great result.
"My final stint on the super-softs was much more difficult because the tyres started graining and I lost a few places. I was thinking I might need to pit again, but fortunately the tyres came back to me for the final few laps so I could save the seventh place. This result for the team is a perfect way to start the season and I want to say a big 'thank you' to the team once again."
Teammate Paul di Resta who finished one position behind was equally content heading into the second race in Malaysia.
"Seventh and eighth for the team is a great result and a great way to kick off the season," he remarked.
"We've shown we have a car that is kind on its tyres and that helped us today by making less stops than some of our rivals. I feel I had a car that could have finished seventh, but I was stuck behind some of the three-stoppers at the start of my second stint, and that cost me quite a lot of track position.
"There are a lot of positives to take from the race, as well as some things that we can improve to make the car stronger, but we're in a good position heading to Malaysia."