Ferrari's Fernando Alonso during the first practice session in Montreal.
Fernando Alonso topped the times for Ferrari in Friday's opening free practice session ahead of this weekend's Canadian Grand Prix.
The 32-year-old Spaniard clocked a best lap time of one minute and 17.238 seconds to finish just 0.016 seconds ahead of nearest rival Lewis Hamilton of Mercedes.
Hamilton's team-mate and championship leader Nico Rosberg was third quickest around the Circuit Gilles Villeneuve as the Mercedes pair resumed their dramatic personal duel for supremacy in this year's title race.
Defending four-time champion Sebastian Vettel was fourth quickest for Red Bull ahead of Valtteri Bottas in the leading Williams and Daniel Ricciardo in the second Red Bull.
Jenson Button signalled a McLaren revival by clocking the seventh best time ahead of his rookie team-mate Kevin Magnussen, Kimi Raikkonen in the second Ferrari and Frenchman Jean-Eric Vergne in the leading Toro Rosso car.
The session produced no major incidents, but a series of minor lock-ups, excursions off-circuit and missed chicanes as the drivers adjusted to the challenges of the tight and unforgiving barrier-lined street track.