Nico Rosberg was understandably happy today after he outpaced his new Mercedes team-mate seven-times champion and fellow-German Michael Schumacher to top the times in opening practice for Sunday's season opening Bahrain Grand Prix.
The 24-year-old son of Keke Rosberg, who was Formula One's original flying Finn, had been expected to struggle against the legendary Schumacher, but proved in their first head-to-head session that he has the pace and the poise to handle the pressure.
And for Mercedes, back in Formula One as an official works team for the first time since 1955, it meant a satisfying return to business with Rosberg fastest and Schumacher third.
On top of that, the German manufacturer supplied the engines to McLaren who took second and fourth places thanks to Britons Lewis Hamilton and defending world champion Jenson Button.
"We improved the car over the course of the day," said a modest and concentrated Rosberg afterwards.
"But it didn't feel great initially with the new track and lower down-force and the conditions were very sandy this morning.
"We had a few balance issues to work on, but it came together very well this afternoon. There are areas where we can still improve, but we have a good comparison with the tyre compounds and on the long runs.
"Overall, I think we learnt a great deal today so it's a positive start to the weekend."
Schumacher, who was half a second slower than his team-mate, explained his relative lack of speed by pointing out that he was only just back in serious action after three years in retirement - and had yet to regain his speed for single flying laps.
He said: "We worked very well this afternoon after having a few issues with the balance this morning.
"For me, the car felt much better in the second session although I am still a little rusty on one lap runs and need to get back into the routine.
"On the long runs, the car felt good and once you get into the rhythm, it feels very natural. I'm happy with our work today and I am feeling ready for the weekend."
Hamilton said he had no idea where he or any others stood in terms of competitiveness for this weekend, following a session in which it was impossible to guess fuel loads.
Hamilton said: "Honestly, I have absolutely no clue. My car feels ok, but I don't know what everyone else is doing. Some people might be heavier, some might be lighter. We might be seriously slow or we might be seriously quick, we just won't know until we go into qualifying tomorrow."
Button said: "I'm happy enough. We're still working on our set-up and that's not something you can really do in the second session because you're on a tyre back-to-back programme and the track's so busy.
"We know where the car is now and we know where we want it to be, so there's work to be done this evening to improve things overnight."
Two-times champion Spaniard Fernando Alonso who was down in ninth place at the end of the afternoon on his debut day for Ferrari said he had no idea who really had the fastest car.
"I think it is impossible to know for now," said Alonso. "I have no idea. I think it's still a complete unknown for everybody.
"For sure the four big teams, any of them can be quick tomorrow, can be on pole. But I'm sure there will be some more surprises."
Alonso's Ferrari team-mate Brazilian Felipe Massa was seventh behind German F1 debutant Nico Hulkenberg of Williams, in sixth place, and another German last year's runner-up Sebastian Vettel in a Red Bull.