Having set the fastest middle sector of the Q3 shootout, Carlos Sainz led the Ferrari attack on home soil as the Spaniard bagged pole position at Monza courtesy of a 1m20.294s effort.
That placed him 0.013 seconds ahead of Red Bull's defending two-time champion Max Verstappen, while Leclerc was 0.067s shy of top spot as he headed the second row of the grid in front of Mercedes racer George Russell.
To cement pole position, both Scuderia drivers also escaped a sporting reprimand from the FIA for exceeding the maximum permitted lap time for their slow out-laps during Q1.
But Leclerc reckoned the result could have improved further and he would have been able to leapfrog Verstappen had he gained a slipstream for his final flying lap, as Sainz did receive.
“My feeling can only be amazing with the Tifosi," said the Monegasque.
“Of course, on my side I'm a bit disappointed. I obviously wanted to be first but seeing that Carlos is P1 is great for Ferrari.
“He has done an incredible job all weekend. I've been struggling quite a bit more: FP1, FP2, FP3 and qualifying I managed to put everything together, so I was really happy.
“Unfortunately, in Q3 I didn't have a slipstream. That probably cost us one position at least, but it's life. We should be happy, especially on my side. I've been struggling a lot.”
Ferrari team boss Fred Vasseur says he remains “convinced” drivers are better off without a slipstream at Monza giving the potential for the turbulent air to upset the cars through the corners. Verstappen also ran without a tow.
Sainz added: “Honestly, it's been such an intense qualifying, especially Q3. We all three went for it, we were very, very on the limit.
“And in that last lap, I knew I had some lap time to come in Ascari and Parabolica, and I went for it. It worked well, because I really pushed hard in that last lap.”
Looking to the race, Sainz said: “I give you everything to hold on to that P1.
“A good start, a good first turn and see if we can battle Max - normally in the long runs he's quicker but I'm going to give it all.”