After seeing Ferrari and Red Bull set the pace in both FP2 and FP3, Mercedes drivers Lewis Hamilton and Nico Rosberg know that they have a real fight on their hands for pole position in qualifying for the Singapore Grand Prix on Saturday night.
Sebastian Vettel headed up a Ferrari one-two in the final free practice session, leading home teammate Kimi Raikkonen to give the Italian marque hope of its first pole position in over three years this weekend.
Both Vettel and Raikkonen displayed a good one-lap pace across the course of practice, and will now be hoping to ward off the threat of the chasing Red Bulls behind.
Daniil Kvyat topped the timesheets on Friday night before finishing third behind the Ferraris on Saturday, and remains a threat as he bids for his first ever pole position in F1.
However, with temperatures dropping as night falls in Singapore, it would be unwise to rule out Hamilton and Rosberg even if they could only finish fifth and sixth in FP3.
You can watch qualifying for the Singapore Grand Prix live on CNBC and Live Extra from 9am ET. CLICK HERE to watch via live stream.