Valtteri Bottas edged out Red Bull's Max Verstappen by just 0.033 seconds to finish fastest in first practice for the Spanish Grand Prix.

The Finn was yesterday forced to deny speculation that he could be replaced by Williams driver George Russell before the conclusion of the season following a difficult start to the new campaign.

But Bottas responded by ending the one-hour running at Barcelona's Circuit de Catalunya fastest of anyone, with Lewis Hamilton third in the other Mercedes. British driver Lando Norris finished fourth for McLaren.

Formula One is gearing up for its fourth race of the season and the next chapter of its mouth-watering championship battle between Hamilton and Verstappen.

Hamilton triumphed last weekend in Portugal to claim his second win of the campaign and extend his championship lead over the Dutchman to eight points.

And on the evidence of first practice, the sport looks set for another tense battle in Spain, with Bottas, Verstappen and Hamilton separated by little more than a tenth in the first action of the weekend.

There was a minor scare in the closing minutes for Bottas when he took evasive action at the chicane to avoid running into the back of Carlos Sainz's Ferrari.

Rookie Nikita Mazepin was in the gravel at turn eight within the opening minutes after he lost control of his Haas. The Russian rookie was able to reverse away from danger before making it back to the pits.

Robert Kubica also found the sand trap, causing the session to be suspended.

The Alfa Romeo reserve driver lost control of his car by carrying too much speed through the new left-handed turn 10 before sliding backwards into the gravel.

The running was stopped for almost 10 minutes as the marshals cleared the Pole's car away from danger.

Charles Leclerc and Sainz finished fifth and sixth for Ferrari, while Verstappen's team-mate Sergio Perez could manage only ninth, more than eighth tenths off the pace.