It's often the most important session of the weekend in Monaco as the narrow confines make overtaking during the race near impossible. A good grid spot is therefore critical for tomorrow's race, a fact that won't have been lost of any of the runners as they prepare for the most glamorous race of the year.
Rain on Thursday allowed Fernando Alonso to top the time sheets in the second practice session but the Mercedes duo of Nico Rosberg and Lewis Hamilton have otherwise dominated the weekend to date. Daniel Ricciardo too has looked strong, even if he complained during final practice that his car hadn't progressed since Thursday.
Though dry and sunny conditions abound today there is rain forecast tomorrow, and while not guaranteed it could prompt some teams to take a gamble on set-up in the hope it is a wet race.
Nico Rosberg is the first to roll out of the garages, followed by teammate Lewis Hamilton as the Mercedes pair opt for the slower soft compound tyre. Queued at the end of the pit lane the Brackley squad is clearly keen to get out on to an empty track to bank a lap early.
Most of the field follows suit, the short Monaco circuit quickly filled. Indeed, traffic is expected to be such a problem race director Charlie Whiting has warned the drivers not to interfere with each other as they look to create space.
Only Daniel Ricciardo and Sebastian Vettel elect to stay in the pits early on, looking for a gap earlier as drivers return to the pits after others complete their first qualifying run.
Daniel Kvyat and Jean-Eric Vergne are the early pace setters as the Toro Rosso pair briefly lock out the front row, though Felipe Massa quickly upsets that with a 1:20.221.
A fastest final sector from Kevin Magnussen is enough to propel him up the order with a 19.484 before Nico Rosberg lowers the benchmark to 17.938. Lewis Hamilton then flashes across the line with an 18.751 to go second.
During practice it had become clear that the trick to a fast lap was to run multiple laps to build up tyre temperature, so it is expected most drivers will stay out for a number of laps in their quest to set a time.
"I damaged my front wing, suspension feels okay," reports Daniil Kvyat who returns to the pits minus a front wing. Replays show a high speed spin as the young Russian loses the car under braking on the bump exiting the tunnel. He's lucky to only drag his front wing down the unforgiving wall.
Ricciardo and Vettel finally emerge from the pits, heading out on the soft compound tyres.
Hamilton looks to respond to Rosberg's lap but falls two tenths of a second off the pace as Felipe Massa goes fourth with an 18.880. Romain Grosjean also improves, putting his Lotus in third place with an 18.835.
"Ericsson wasn't on a lap and he's just held you up," is the message from Force India to Nico Hulkenberg. "Absolutely," comes the response from the German.
Vettel's first timed lap is just 21.288, a slow warm up lap ahead of a fast lap. Ricciardo was less patient and immediately he goes third fastest.
With seven minutes remaining those in danger are the spinning Kvyat, Ericsson and Kobayashi, Sergio Perez, Nico Hulkenberg and Max Chilton. Just on the fringes in 16th is Jules Bianchi, a tenth ahead of Hulkenberg with a 19.332 and just half a tenth adrift of Valtteri Bottas.
Hulkenberg's attempts to extract himself from the bottom six are thwarted by Romain Grosjean, the Lotus driver is shown blue flags but as he's on hot a lap he refuses to let the Force India through. Instead the Hulk slows to create space while teammate Sergio Perez is also in traffic in a busy session on track.
A lock up from Kevin Magnussen sees him run wide at Ste Devote, a flat spotted set of the precious supersoft tyres his reward.
With three remaining Hulkenberg remains in the bottom six while Kimi Raikkonen in fifteenth is too close for comfort. The Finn soon changes that with a time of 18.902 to go fifth, as Hulkenberg also improves to go twelfth.
That leaves Sutil, Bianchi, Chilton and the Caterhams in the drop zone. Kvyat, the early pace setter, has been demoted to sixteenth, placing the Toro Rosso driver in danger as the yellow flags fly at Mirabeau.