Max Verstappen put in another impressive performance in second practice to top the timing sheets, but Fernando Alonso ramped the pressure up on both Red Bull and the Dutchman after he ended up just 0.170secs behind him in second place.
Having finished first practice 0.7s clear of team-mate Sergio Perez in second, Verstappen looked set to dominate yet another race weekend as he posted a session best time of one-minute 13.907s.
But on his home circuit, Alonso made sure that the two-time world champion will be checking his rear-view mirrors ahead of Saturday's qualifying.
The F1 veteran, who finished nearly a second behind Verstappen in first practice, roared back to life in the following session to end up within two-tenths of the Red Bull driver.
Elsewhere, Nico Hulkenberg gave hope to Haas after he stunned the crowd to finish third-fastest, just 0.270s off Verstappen.
Sergio Perez and Esteban Ocon rounded off the top five as they finished fourth and fifth respectively.
Unfortunately for Mercedes, their struggles during first practice continued as George Russell and Lewis Hamilton found themselves in eighth and 11th respectively.
The teams will now have to work hard in order to fine-tune and tweak their cars ahead of FP3 and qualifying on Saturday.