Nicholas Latifi ended the two free practice sessions for this weekend's British Formula 3 International Series round at Spa on top of the times.

The Canadian's time from the morning session, which was 0.765 seconds clear of Carlin team-mate Jordan King, was unbeaten in the afternoon's 35-minute period, in which Latifi was one of only two drivers not to improve.

King topped that session with a last-lap effort to pip Latifi by just seven thousandths of a second.

The other Carlin driver, Jann Mardenborough, was just one hundredth off the pace as he gears up for a busy weekend in which he will also contest the Spa 24 Hours in a Nissan.

The second session began on a track that was damp off line after a heavy lunchtime shower, but it soon dried out in the hot sunshine.

Latifi's effort was particularly strong as he has never raced at the Belgian track, while King competed here in Formula Renault last year and Mardenborough raced in last year's 24 Hours.

King said: "There's only eight of us [in the International Class], and with the weather changing it's hard for us to judge how we're going, and some people are on new tyres and some not. It's all a bit random, but I think we're all right."

Antonio Giovinazzi was half a second clear of Sean Gelael as the Double R Racing pair ended fourth and fifth, with team-mate Tatiana Calderon eighth.

Pre-weekend favourite Will Buller, who took maximum points at Spa in the two non-reversed-grid British F3 races in 2011, edged out Fortec team-mate Felipe Guimaraes for sixth, as the squad worked on experimenting before qualifying later today.

In the three-car National Class, China's Sun Zheng was more than two seconds clear of his opposition.

Practice one

Pos Driver                         Team/Car                            Time     Gap          

 1. Nicholas Latifi            Carlin Dallara-VW               2m16.419s

 2. Jordan King               Carlin Dallara-VW               2m17.184s  +0.765

 3. Jann Mardenborough   Carlin Dallara-VW               2m17.225s  +0.806

 4. Antonio Giovinazzi      Double R Dallara-Merc         2m18.303s  +1.884

 5. Tatiana Calderon       Double R Dallara-Merc         2m18.923s  +2.504

 6. Felipe Guimaraes        Fortec Dallara-Merc           2m19.039s  +2.620

 7. Will Buller                 Fortec Dallara-Merc           2m19.094s  +2.675

 8. Sean Gelael              Double R Dallara-Merc        2m19.273s  +2.854

 9. Sun Zheng               CF Dallara-Mugen              2m21.913s  +5.494 Nat

10. Jordan Oon              West-Tec Dallara-Toyota    2m23.324s  +6.905 Nat

11. Chris Vlok                West-Tec Dallara-Toyota    2m24.761s  +8.342 Nat

Practice two

Pos Driver                       Team/Car                              Time     Gap     

 1. Jordan King              Carlin Dallara-VW                2m16.708s      

 2. Nicholas Latifi           Carlin Dallara-VW                2m16.715s  +0.007s

 3. Antonio Giovinazzi      Double R Dallara-Merc         2m16.718s  +0.010s

 4. Jann Mardenborough   Carlin Dallara-VW               2m17.243s  +0.535s

 5. Sean Gelael               Double R Dallara-Merc         2m17.792s  +1.084s

 6. Will Buller                  Fortec Dallara-Merc            2m17.825s  +1.117s

 7. Felipe Guimaraes        Fortec Dallara-Merc            2m17.925s  +1.217s

 8. Tatiana Calderon       Double R Dallara-Merc          2m18.844s  +2.136s

 9. Sun Zheng               CF Dallara-Mugen                2m20.463s  +3.755s Nat

10. Jordan Oon              West-Tec Dallara-Toyota     2m22.722s  +6.014s Nat

11. Chris Vlok                West-Tec Dallara-Toyota     2m25.103s  +8.395s Nat.

(autosport.com/marcus simmons/ARL)