The German, who last won on the Champs Elysees at the Tour de France, hit the front with 150 metres to go on the stage to Castle Douglas, with Caleb Ewan (Orica-BikeExhange) finishing second.
"It's always nice to start of with a victory. We're setting goals to win a stage and we've reached that on the first day. We can be happy," a beaming Greipel said as he sat down for his stage winner's press conference in the Legions Club bar.
A crash in the final tight lefthand corner took out a number of Greipel's rivals, including Mark Cavendish (Dimension Data), but Greipel's dominant performance capped a successful day for his Belgian team after they had worked throughout the stage.
"It's not always easy to make a leadout with six guys. We had to chase down the break and we did a good job to keep me up there in the last corner. I had a really good leadout until the final 150 metres with Marcel Sieberg and Jens Debusschere in front of me. Of course I'm happy to finish it off."
Lotto Soudal came into the Tour of Britain with a number of ambitions and stage 2 from Carlisle to Kendal could see a number of the GC hopefuls come to the fore. In Tony Gallopin, the Belgian team has a rider capable of securing a second stage win.
"It's going to be quite tough but with Gallopin we have a rider to support there for a day like that and we're going to try."
Greipel versus Kittel for Worlds leadership?
Since the Tour de France, Greipel has taken a break from racing before returning at the end of August with a 10th-place finish at the Hamburg Classic.
"I had a bit of a break after the Tour and from there I tried to stay focused and worked hard. Now I start in the race mode again and I'm happy to win here on my first day.
"I think this race is in a good spot in the calendar and I chose this race because it helps towards my up coming goals. I just try my best."
The second half of the season builds towards the World Championships in Doha in October, where the sprinters are expected to dominate on a flat course. Germany is blessed with three leading fastmen in Greipel and Marcel Kittel – who coincidently won today at the GP de Fourmies – and John Degenkolb, although the route potentially favours the first two.
In a previous interview with DPA, Greipel had said that he would not accept going to Worlds as a second option and that he desired the leader's spot. When asked about the situation and team leadership today, the elation at winning was replaced by a sterner front.
"We can speak about the Tour of Britain. Not about the Worlds."
When asked for his thoughts on the selection of the national team, he only added: "I can't make thoughts because it's not up to me."