Ricciardo ends the morning on top in Bahrain

Red Bull's Daniel Ricciardo topped the timesheet at Sakhir this morning on day 1 of this week's in-season test at Bahrain.

The Aussie was fastest on the back of a series of short runs, achieving a 1:32.349 with supersoft tyres, just edging out Lewis Hamilton.

The Mercedes fell victim to an electrical problem early on which brought out the red flag but, disrupting the team's programme which is centered around getting a better understanding of tyre wear and temperatures, a major weakness in last Sunday's Bahrain GP.

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Hamilton was able to resume his running although it took close to 30 minutes to get his W08 back to the pits.

A second red flag came out rookie Sean Gelael parked his Toro Rosso after a suspected engine failure. The Indonesian is set to return to action when the team completes replaces his Renault power unit.

McLaren-Honda's prospects for the day were hit when a water leak was discovered in the ERS, keeping Oliver Turvey out of the action

GALLERY: All the action from the Day 1 in-season testing at Bahrain

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Phillip van Osten

Motor racing was a backdrop from the outset in Phillip van Osten's life. Born in Southern California, Phillip grew up with the sights and sounds of fast cars thanks to his father, Dick van Osten, an editor and writer for Auto Speed and Sport and Motor Trend. Phillip's passion for racing grew even more when his family moved to Europe and he became acquainted with the extraordinary world of Grand Prix racing. He was an early contributor to the monthly French F1i Magazine, often providing a historic or business perspective on Formula 1's affairs. In 2012, he co-authored along with fellow journalist Pierre Van Vliet the English-language adaptation of a limited edition book devoted to the great Belgian driver Jacky Ickx. He also authored "The American Legacy in Formula 1", a book which recounts the trials and tribulations of American drivers in Grand Prix racing. Phillip is also a commentator for Belgian broadcaster Be.TV for the US Indycar series.