Racing Point's Sergio Perez pipped Red Bull's Max Verstappen to take fastest time in first practice at the Styrian Grand Prix.
The event is the second in a week at the Red Bull Ring, the first time two races have been held at the same track in the same year in Formula 1 history.
Perez was 0.096 secs ahead of the Red Bull, with Mercedes' Valtteri Bottas and Lewis Hamilton third and fourth.
Bottas won the delayed season-opening race last weekend.
Styrian Grand Prix coverage on the BBCHamilton, who is already 13 points behind Bottas after a messy race last time out, was 0.031secs slower than his team-mate.
Bottas was 0.222secs slower the Perez, driving what has been dubbed the 'Pink Mercedes' because of its likeness to last year's championship-winning car, which Racing Point admit they have copied.
Ferrari spent the session evaluating new parts after a dismal performance in qualifying last weekend, when they were close to a second off the pace - and off the time they set themselves last year.
Ferrari have a new front wing and revised floor, which Charles Leclerc tried out.
F1 Breakdown: Jack Nicholls previews new Formula 1 seasonLeclerc ended the session 12th fastest, two places behind team-mate Sebastian Vettel.
It was a largely uneventful session, although Alpha Tauri's Daniil Kvyat had a spin at Turn One and Williams driver Nicholas Latifi suffered an engine problem that stopped him out on track mid-way through.
It is the second engine issue in consecutive races for Williams, after George Russell was forced to retire from the Austrian Grand Prix last weekend.
Russell has started this race weekend with a new engine, turbocharger and MGU-H hybrid unit as a result.
Russell did not take part in this session as his car was being used by British driver Jack Aitken, Williams' reserve driver making his first appearance on an F1 weekend.
Aitken ended up 17th fastest, ahead only of Alfa Romeo reserve driver Robert Kubica, standing in for Antonio Giovinazzi.