Nico Rosberg was the fastest man in the opening practice session for the Malaysian Grand Prix.
The German posted a 1:40.124 early in the 90-minute session as the Mercedes ended the session just under four tenths clear of the Ferrari of Kimi Raikkonen after a late run in a higher engine mode saw the Finn close the gap.
It was a far from ideal morning, however, for Rosberg's team-mate Lewis Hamilton as the Briton suffered a lack of telemetry from the start of the session and it would get worse for the world champion as he was forced to stop out on track with an engine problem that required a power unit change for the afternoon session.
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The time lost for Hamilton, about an hour in total, was less of an issue than it first appears as blustery conditions and a very low level of grip on the Sepang circuit meant times were much slower than perhaps had been expected.
Manor Marussia hit the track
At the back of the grid there was a rare feel-good story to talk about as, after being stuck in the garage all weekend in Australia, Manor Marussia finally made their track debut and were among the first cars out on Friday morning.
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With zero miles on the clock heading into the weekend, unsurprisingly it was a slow start for the salvaged remains of the former Marussia outfit, with Will Stevens posting their fastest time of a 1:46.686, however, comparing their first 90-minutes of running to the other teams on the first day of testing a combined 16 laps isn't too bad of a start.
For them the main aim will be to complete as much mileage as possible and should they first qualify within the 107% mark needed and then reach the chequered flag on Sunday it will be another huge step taken.
Alonso shows no crash effects upon McLaren return
After missing the first race recovering from his crash in pre-season testing late last month, fans finally got to see Fernando Alonso back in McLaren chrome for the first time since 2007 as the Spaniard makes his anticipated return.
With the conversation still raging over just what happened in Barcelona, following comments the former double world champion made on Thursday, Alonso was showing no after effects back behind the wheel completing a standard first practice with 19 laps and ending just over two tenths faster than Jenson Button.
However, McLaren are still being very conservative in winding up the performance from the Honda power unit as Fernando was 2.7 seconds slower than Rosberg in 14th place.
Ferrari again best-of-the-rest
In the battle for the final place on the podium, Williams stuck by their traditional methods of not revealing much their hand on Friday morning.
Instead it was Ferrari who again moved in behind the sole Mercedes of Rosberg as Vettel all butt matched Kimi Raikkonen's early effort with a 1:40.985 only for the Finn to put in the fastest first and third sectors to move half a second clear in the final minutes.
For the record Valtteri Bottas was eighth quickest in his first session back since injuring his back in qualifying two weeks ago in Melbourne - three tenths faster than Felipe Massa who had an issue with a leaky drinks bottle, something that could be very painful in the searing heat if it was to happen in the race. Both were over a second slower than the Prancing Horse's
Strong midfield battle awaits
A very competitive scrap for the final points positions is developing with just 1.6 seconds covering Romain Grosjean's Lotus in fourth, to Jenson Button's McLaren in 17th.
The two Red Bull teams were closely matched as they formed a little cluster in the middle of the top ten. Carlos Sainz was fifth in the Toro Rosso leading Daniel Ricciardo, who's session was curtailed by a mechanical issue, in sixth, Max Verstappen was seventh following his first laps at Sepang with Daniil Kvyat just failing to complete a full compliment as he was ninth in the second RB11.
Lotus and Sauber make it a four-way battle with Grosjean leading the midfield pack and team-mate Pastor Maldonado in 11th while Sauber were perhaps a little off where they will be as Felipe Nasr gave way to allow Ferrari academy driver Rafaelle Marciello his first official run in an F1 car with the Italian a respectable 13th albeit six tenths behind Marcus Ericsson.
Force India & McLaren to rekindle 2014 rivalry
Seemingly unable to join the main midfield pack, the under-developed Force India and McLaren teams may enjoy a re-run of the rivalry that ran all the way through the 2014 season.
At Vijay Mallya's team it remains the chassis that is holding Sergio Perez and Nico Hulkenberg down as they look to maximise gains from a switch to the Cologne windtunnel used by Toyota and Ferrari in recent years. While at Ron Dennis' squad it is all about the slow process of extracting the performance out of the Honda power unit.
It seems another high attrition race maybe needed if the two teams are going to get near the points, however, given the issues at Mercedes and Red Bull it may just be the case.