Darron Cummings/Associated Press

Nico Rosberg will start Sunday's US Grand Prix at the Circuit of the Americas in Austin, Texas, from pole position. Beating teammate Lewis Hamilton by a wide margin in the final qualifying session, the German dealt out a psychological blow with the title race winding down.

Just three races are left on the calendar, and with the top contenders for the world title separated by a mere 17 points, no one can afford a poor result on Sunday.

Lewis Hamilton holds the advantage thanks to a phenomenal second half of the season, but Mercedes teammate Nico Rosberg will be aided by the fact the final race of this season will award double points, all but ensuring the title will be decided in Abu Dhabi.

The German can't afford a poor result in Austin, however. With the win in the inaugural Sochi Grand Prix, Hamilton has now won the last four races since his retirement in Belgium.

Austin's track filled with long, high-speed turns is tailor-made for the Brit, who won here in 2012. As long as his Mercedes holds up mechanically, a finish in the top two is almost a given.

Rosberg will have to do the same and perhaps even better his teammate's result, setting the stage for an epic finale in the last two races.

The McLaren duo of Valtteri Bottas and Felipe Massa will start from the third and fourth spot, respectively, while four-time World Champion Sebastian Vettel will be forced to start from the pit lane.

Darron Cummings/Associated Press

Lewis Hamilton took the top spot in all three practice sessions, but Mercedes teammate and world title-rival Nico Rosberg will start Sunday's US Grand Prix from pole position after going fastest in Q2 and Q3.

The German was over .3 seconds faster than Hamilton, who seemed to have difficulty navigating the middle sector and complained of locking brakes during Q2.

As reported by NBC's official F1 Twitter feed, he spent more time in the pit lane than he would have liked and claimed his brakes locked up even when he didn't push them, per NBC's Will Buxton.

That shouldn't take away from Rosberg's phenomenal run, however. Trailing Hamilton by 17 points in the race for the title, a good result in Austin is sorely needed. An incredibly sharp time of 1.16:067 is an excellent start, laying down the marker for his Mercedes teammate.

McLaren have looked strong throughout the weekend and confirmed their form during qualifiers, as Valtteri Bottas and Felipe Massa will start Sunday's race from the second row.

Jenson Button put together the seventh-best time but will drop back to 12th, the result of a five-place grid penalty for a gear box change.

Sebastian Vettel will start from the pit lane and wasn't expected to participate in qualifying, but he gave his Red Bull a few laps during the first session.

Rosberg was obviously happy with the result of the qualifying session, but refused to get ahead of himself, via BBC Sport:

Great day, very happy. It worked out really well. Together with my engineers, I arrived in qualifying with a car that I was really happy with for qualifying.

This morning, the conditions were quite different so it wasn't easy to get everything right. First place today is awesome, but the race is what counts, so I need to fully focus on tomorrow and try and bring it home. Of course the start is going to be important, I need to make the most of that and stay ahead.

The full results for the qualifying session, courtesy of formula1.com:

Darron Cummings/Associated Press

Mercedes waited until the final 30 minutes of the third and final practice session to set their times, and Lewis Hamilton once again set the fastest lap time, by more than .8 seconds.

Nico Rosberg's simulation run was delayed by a glazed break disc and he was told to slow down before his flying lap to keep a healthy gap between himself and Sebastian Vettel, limiting the German's opportunities to gain on his Mercedes teammate.

Valtteri Bottas took the early lead when he became the first driver to go under 1.38:00, but Fernando Alonso and Felipe Masa pushed him back down the pecking order within minutes.

Mercedes and Red Bull decided to take a slower approach to the practice session, however, with temperatures expected to rise significantly ahead of the qualifying session.

With 25 minutes left in the session, both Hamilton and Rosberg finally came out for their laps. The Brit spun out after a few laps in Turn 12 before returning to the pit lane for his soft tyres. Rosberg struggled in the same corner, and he too returned after a few minutes.

This meant both titans would set their times with mere minutes left in the session, and after Hamilton smashed Massa's then-quickest time, Rosberg was delayed by Vettel and had just one opportunity to better his position after that flying lap.

Hamilton has so far dominated every practice session, and Saturday's showing was perhaps the most impressive of them all. It must be a discouraging sign for the rest of the pack to see the Mercedes continue to thrash their times, as it appears the margin is only improving.

Williams have made a good impression in Austin so far and McLaren have an opportunity to make some noise during Sunday's race, but barring mechanical failure, the two top spots have already been set, with championship leader Hamilton the strong favourite.

The full results, courtesy of Formula1.com:

David J. Phillip/Associated Press

Lewis Hamilton was once again the fastest driver during the afternoon session, but concerns with the gear box and a fuel leak prematurely ended his day, not allowing him to test the car for a long run.

Nico Rosberg had the same issues but didn't require a return to the pit lane, and the German will carry the advantage of having made a long run into Saturday's qualifying session and Sunday's race.

The Mercedes cars predictably took the top spots for the second straight session, but behind the duo of Rosberg and Hamilton, an interesting battle developed. Red Bull and their lighter engines lost the battle to Fernando Alonso's Ferrari, while McLaren continue to look strong, placing more of an emphasis on the long runs.

Sebastian Vettel in particular disappointed for Red Bull, and as it stands, the four-time World Champion seems unlikely to play a significant part in Sunday's race.

No team had more issues with the Circuit of the Americas than Lotus, however, as the duo of Pastor Maldonado and Romain Grosjean continued spinning out all over the track. The team's official Twitter feed even started taking shots at its own drivers, to the hilarity of fans on social media.

Hamilton remains the favourite for Sunday's race, having won here in 2012, but the issues with his Mercedes are something to keep an eye on. The Brit lost a ton of vital championship points due to mechanical failure in the early part of the season, and at this stage of the campaign, a disappointing finish can be lethal.

The full results for the second practice session, courtesy of Formula1.com:

Darron Cummings/Associated Press

Lewis Hamilton was the only driver capable of dipping under 1:40.00 during Friday's first practice session, going three tenths of a second faster than Mercedes teammate Nico Rosberg with a time of 1:39.941.

Jenson Button took the lead early and looked strong throughout the first session, but his excellent efforts could come undone as McLaren confirmed the Brit has been hit with a five-place grid penalty for an unscheduled gearbox change, as reported by NBC Sports' Luke Smith.

Sebastian Vettel wasn't even expected to take part in qualifying as he will alter the power unit on his car completely, forcing him to start from the pit lane, but he came out for the first practice session in Austin and clocked in the seventh time.

Red Bull teammate Daniel Ricciardo was sidelined by an ERS issue for much of the session, and as a result, he could do no better than 17th.

But once again, all eyes were on the Mercedes duo, who dominated large parts of the session to take the two top spots, on pace for their 10th one-two of the season.

Winning here in 2012, Lewis Hamilton clearly feels comfortable on Austin's long, sweeping corners. If his first practice session is any indication, the Brit could use this weekend to put the world title race to bed.

Rosberg has other ideas, however, and with the final race in Abu Dhabi carrying double points, anything can happen. Hamilton hopes it doesn't come to it, as he told BBC Sport's Andrew Benson:

It would suck if that was the case—big time.

But I'm not even going to put that negative energy out there. I'm just going to try and do the best job I can with the car that I have and what will be will be, I guess.

This is the rule that they have brought in for the first time.

Do I really agree with it? I don't know if any of us agree with it or do not agree with it, but it is the way it is and you just have to deal with it and just hope for the best really.

The full results for the first practice session, courtesy of Formula1.com: