errari new boy Felipe Massa set the pace at Barcelona as some of Formula 1's big guns came out to play for the first time in open testing.
While Massa put more miles on Ferrari's V8 engine, Kimi Raikkonen tried McLaren's new MP4-21 for the first time and Micheal Schumacher blooded in Ferrari's new 248 F1 in serious company.
Massa's time of 1m15.970s was largely irrelevant for while the Brazilian was using a V8, it was bolted to an old F2004 chassis.
More significant was Rubens Barrichello's best lap of 1m16.361s, which made him the fastest runner driving a 2006 machine.
Testing is testing and while it is unwise to read too much into times Barrichello will no doubt be pleased that not only was the Honda so fast so early on, but also that his car was 0.4s faster than team-mate Jenson Button's.
Splitting the Hondas were Giancarlo Fisichella's super-consistent Renault R26, just 0.04s behind Barrichello, and Nick Heidfeld's impressive new BMW.
The BMW-Sauber team has now concluded its running for the week and while test driver Robert Kubica ended the day 13th fastest, technical director Willy Rampf praised the Pole's progress.
"I am very satisfied with the debut of Robert in our team," he said.
"Over two days, he didn't make the smallest error, and he was able to improve constantly."
Fernando Alonso was sixth fastest having completed a race distance and a spin while David Coulthard was seventh in the new Red Bull RB2.
Schumacher was only eighth fastest in the new Ferrari although its early days for the 248.
Jarno Trulli and Ralf Schumacher pounded through Bridgestone's tyre collection to the ninth and tenth fastest times while Vitantonio Liuzzi had a run-out for Scuderia Toro Rosso.
Raikkonen spent most of the morning in the garage but the Finn did manage 65 laps in the car he hopes will bring him his first title.
In fact although he was only 12th fastest on the day, two spots ahead of team-mate Pedro de la Rosa, the Finn declared himself pretty happy with MP4-21.
"It is really good to be back testing and to see what the team has done with the new car," he said.
"My first impression of the car is positive, but I will need more track time to find out how great the potential really is."
Thursday's testing times from Barcelona
1. MASSA Ferrari 1m15.970s
2. BARRICHELLO Honda 1m16.361s
3. FISICHELLA Renault 1m16.365s
4. HEIDFELD BMW 1m16.549s
5. BUTTON Honda 1m16.739s
6. ALONSO Renault 1m16.754s
7. COULTHARD Red Bull 1m16.885s
8. M.SCHUMACHER Ferrari 1m16.907s
9. TRULLI Toyota 1m17.250s
10. R.SCHUMACHER Toyota 1m17.506s
11. LIUZZI Red Bull 1m17.590s
12. RAIKKONEN McLaren 1m17.741s
13. KUBICA BMW 1m17.992s
14. DE LA ROSA McLaren 1m18.258s