So the Ferrari duo finished top of the tree in FP1 but will they lead the standings in FP2?

Colton Herta's mechanical issues meant we lost some time in this first session but the conditions are perfect in Monza this weekend so any further time lost won't be down to the weather that's for certain.

But can anyone challenge the Prancing Horse at the Temple of Speed?

We'll be back for FP2 at 14:45 BST.

11. Oscar Piastri (McLaren)

12. Yuki Tsunoda (Racing Bulls)

13. Nico Hulkenberg (Audi)

14. Oliver Bearman (Haas)

15. Luke Browning (Williams)

16. Carlos Sainz (Williams)

17. Ayumu Iwasa (Red Bull)

18. Esteban Ocon (Haas)

19. Valtteri Bottas (Cadillac)

20. Lance Stroll (Aston Martin)

21. Fernando Alonso (Aston Martin)

22. Colton Herta (Cadillac)

1. Charles Leclerc (Ferrari) 1:23.008

2. Lewis Hamilton (Ferrari) +0.173

3. George Russell (Mercedes) +0.304

4. Liam Lawson (Red Bull) +0.425

5. Kimi Antonelli (Mercedes) +0.636

6. Lando Norris (McLaren) +0.711

7. Arvid Lindblad (Racing Bulls) +0.794

8. Gabriel Bortoleto (Audi) + 0.998

9. Franco Colapinto (Alpine) +1.020

10. Paul Aron (Alpine) +1.169

Lewis Hamilton goes off and into the gravel in the second chicane.

Not that it's diminished his fervour as he's still second fastest on track right now.

Not a great deal of time left in FP1 right now.

And there's been very little movement at the top for quite some time.

1. Charles Leclerc (Ferrari) 1:23.008

2. Lewis Hamilton (Ferrari) +0.173

3. George Russell (Mercedes) +0.304

4. Liam Lawson (Red Bull) +0.425

5. Kimi Antonelli (Mercedes) +0.636

Just 10 minutes left on the clock, now.

A reminder that we lost a good five minutes earlier on due to a red flag caused as Colton Herta, in a rookie FP1 session with Cadillac, had to park his car at the side of the track due to a mechanical issue.

Will we see the times venture into the 1:22s by the end of this session?

Charles Leclerc's fastest time is just outside of that marker as his Ferrari team-mate Lewis Hamilton - on a set of mediums - goes second fastest with a 1:23.181.

Just under 20 minutes left on the clock, folks.

And it's as you were at the top of the standings.

Charles Leclerc's 1:23.008 leads the way, followed by George Russell three tenths behind and then Lewis Hamilton.

Not a bad showing from Ferrari in this first session.

I'm not sure what's gone on there but Kimi Antonelli goes into the gravel at the turn one chicane...and he's followed by Lando Norris...and then Carlos Sainz.

They all make the same last-ditch move off-track. How strange.

Image source, Getty Images

The two Ferraris sandwich second-placed George Russell right now as Lewis Hamilton goes third fastest.

Championship leader Kimi Antonelli, with a new engine for this weekend, is fourth.

Charles Leclerc gives the Tifosi reasons to be cheerful as he guides his Ferrari into top spot with a 1:23.008.

Further down the order, Paul Aron's currently the best of the rookies as he occupies 13th place so far.

Andrew Benson
BBC F1 correspondent at Monza

McLaren have won their appeal against the result of the Monaco Grand Prix after a controversy over multiple incorrect pit-lane speeding penalties.

The victory means Alpine's Pierre Gasly loses the podium he was awarded after an appeal by the French team that overturned two five-second penalties.

That means Gasly, who finished third on the road, is dropped back to the seventh place he received in the official results.

Red Bull's Isack Hadjar is returned to third place and McLaren's Oscar Piastri fourth for the race which took place on 7 June.

There were multiple speeding penalties because Formula 1 had incorrectly measured the length of the pit lane, meaning cars' average speeds were adjudged wrongly to be too high.

Read more on the developing story here.

Image source, Getty Images

And the pit lane is back open. We've lost the best part of five minutes of the session, there.

Given how infrequent these rookie FP1 sessions are, that's bad luck for Colton Herta if his time behind the wheel of Sergio Perez's Cadillac is over.

The session will resume at 12:56 local time.

That's 11:56 BST.

So while we wait for things to get going again. What's the lay of the land?

Well Lando Norris, fresh from two successive Grand Prix victories, leads the way with a 1:23.719 in his McLaren.

Just 0.083 seconds separates him from George Russell while Lewis Hamilton makes it an all-British 1.23 top three with his 1:23.891.

Red flagpublished at 11:50 BST

11:50 BST

The marshals are trying their best to give Colton Herta's Cadillac a nudge with the car seemingly stuck in gear.

In the mean time, the session is red flagged with the car still stuck at the side of the track.

Colton Herta's come to a standstill just beyond turn five.

The rookie pulls his Cadillac to the side of the track. Not great just 20 minutes into the session.

There's not a set tyre choice right now on track. It's a mix between hard and medium so far.

But Kimi Antonelli has joined Liam Lawson in donning a set of softs.