With under two tenths separating the top five, there's the possibility for an almighty fight for pole position in qualifying.
Sainz shockingly set his best time with the medium tyre, as the grid battles with an overheating soft tyre which is tricky to manage for a whole lap.
It could mean that some teams opt to use the medium in Q3 as they harder Pirelli rubber manages to hold on throughout the entire lap through Albert Park.