Barcelona F1 test: Lewis Hamilton fastest while McLaren struggles

The 30-year-old Mercedes driver, running the medium tyres, outpaced Williams's Felipe Massa by 0.882s with Red Bull's Daniil Kvyat two tenths further adrift.

It was the ninth-quickest lap of Barcelona testing so far, but second fastest on the mediums, behind only team-mate Nico Rosberg's effort from the previous test.

Hamilton headed back out later in the morning and completed an eight-lap run on the mediums, consistently lapping in the high-1m26s and low-1m27s.

He followed that up with a 12-lap run, again on the mediums, starting in the high-1m24s and dropping into the mid-1m26s by the end.

The Briton clocked up the most laps with 48 to complete another strong morning for the reigning world champion team at the Circuit de Catalunya.

The same cannot be said for McLaren, with Jenson Button spending most of the morning in the garage.

Of the seven laps the 2009 world champion did complete, only one of them was timed and that was good enough for eighth - and last (due to Force India not running) - on the timing screens.

Kvyat caused the only red flag of the morning just 10 minutes into the session when the Russian stopped his RB11 at the pitlane exit.

But the 20-year-old returned later on the medium tyres to clock the third quickest time.

Elsewhere, Lotus' Romain Grosjean and Sauber's Marcus Ericsson clocked up 33 laps apiece on their way to fourth and fifth on the leaderboard, while Ferrari's Kimi Raikkonen was sixth.

Toro Rosso has introduced a host of new upgrades for this test, including a Williams-style stumped nose which replaces a rounded design used in the previous two tests.

Carlos Sainz Jr spent much of the morning completing in and out laps in what technical director James Key described as "almost a completely brand new" car before getting his first time on the board with 90 minutes to go. The Spaniard ended up seventh quickest.

Unexpected light drizzle inside the final hour of the session meant most drivers chose to stay in their garages with only Kvyat and Hamilton venturing out on Pirelli's intermediate tyres.

DAY ONE MORNING TIMES