Bad news for Muroya, who will fall behind Sonka in the overall standings with just two races to go after this weekend
Next head to head is the second of the Czech pilots
Petr Kopfstein flies against the current standings leader, Kirby Chambliss
178.44kts and Kopfstein is in the track
This is very steady and disciplined flying...
His time will be the marker for Chambliss and this is a clean and pretty perfect performance
First time racing along the Douro for Kopfstein, while Chambliss has raced here three times in the past
It's a 1:08.452 for Chambliss to beat – this could go either way
Realistically Chambliss will have to pick up a penalty for Kopfstein to progress and he's been on good form already today so we're not expecting that
Will Chambliss make it three in a row today?
179.53kts for Chambliss into the track
And he's green from the off... this is the calibre of a former World Champion
And he's green all the way and secures his place in the Final 4 – taking him closer to that third win!
It's a 1:07.835 for Chambliss and he's through!
Two remaining head to heads – McLeod V Dolderer and Brageot V Hall
Muroya: The plane was accelerating more than I thought. That makes the game difficult but it's not the end.
Sonka: Yoshi made it a little easier for me and I knew I didn't have to push too much. A very nice duel with him.
Chambliss: We'll probably have to step it up a little bit. I'd like to see a 1:07 flat.