Lando Norris led Formula 1 leader Oscar Piastri in a McLaren one-two in second practice for the Austrian Grand Prix on Friday after George Russell went fastest for Mercedes in the opening session.
Norris had handed his car to Alex Dunne for an impressive F1 practice debut for the Irish rookie and Formula 2 leader, but the Briton was right up to speed as soon as he got back behind the wheel.
After Russell's best of 1:05.542 in the early afternoon, Norris -- 22 points behind Piastri in the title battle after 10 of 24 races -- lapped in 1:04.580 with Piastri 0.157 slower.
Red Bull's reigning champion Max Verstappen, a five-times winner at his team's home circuit, was the only other driver under the five second mark with a 1:04.898.
Russell, winner from pole position in Canada two weeks ago after the McLarens collided, was sixth in practice two with Lance Stroll a surprise fourth for Aston Martin and Charles Leclerc fifth for Ferrari.
Verstappen was without regular race engineer Gianpiero Lambiase for the weekend due to personal reasons with Simon Rennie taking over.
Dunne, given track time as part of team obligations to give rookie drivers F1 experience, was the talk of the first session when he lapped fourth fastest and only 0.069 slower than Piastri.
Still only 19 and the first Irish driver in 22 years to take part in a grand prix weekend, he thanked the team over the radio as the chequered flag fell.
"A little boy's dream came true, and this is definitely the best day of my life," he said. "Thank you everyone for letting me do this, and thanks to Lando as well for trusting me with his car."
McLaren team boss Andrea Stella cautioned not to read too much into the time, however.
"Alex has been quite diligent and impressive, and then he also had the chance to show some speed and, no surprise, he is a fast driver," the Italian said.
"I think we need to be a bit careful looking at the lap times, because his came later on in the stint when the fuel was down. But I think encouraging and impressive in terms of Alex himself, and also I think a good session for McLaren."
Austria has the shortest lap of the year in terms of time and all but 20th-placed Haas driver Oliver Bearman were within a second of Russell in the opening session.
Seven-times world champion Lewis Hamilton was ninth and 10th respectively in the sessions as Ferrari made a difficult start to their preparations with mechanics working on both cars during practice one.
Hamilton was also warned for impeding Mercedes' Kimi Antonelli.
"I didn't see Antonelli," he said over the radio after the Italian went wide to avoid a collision.
Leclerc sat out that session with Swedish reserve Dino Beganovic getting some track time and finishing 18th.
Fernando Alonso had a big spin in his Aston Martin but kept the car out of the barriers.