The Toyota Gazoo Racing driver, who starts this week’s FIA World Rally Championship finale 21 points behind leader Elfyn Evans, stopped the clocks at 2min 30.4sec on his second pass through the 3.27km Olmedo-Monte Baranta test.
That left him 0.3sec clear of Toyota team-mate Takamoto Katsuta, with Hyundai’s Thierry Neuville another tenth further back.
Solberg was in an upbeat mood ahead of a weekend in which he knows only a major swing in points can deliver a maiden world title.
“It is going to be very exciting,” he said. “It will be a long shot, that is for sure, but everything is possible. I took 20 points on Elfyn at the last rally and I’m only 21 points behind.
“There will be a lot of cleaning here, I think. We will see.”
Road cleaning and hanging dust quickly emerged as major talking points during the morning, with the dry Sardinian gravel producing challenging conditions for several crews.
Championship leader Evans ended shakedown sixth fastest, 2.1sec away from Solberg’s benchmark, and expects his first-on-the-road position to provide a stern test when the rally moves onto the longer stages on Friday.
“The preparation has been the usual,” Evans explained. “This is a flavour of what is to come - it is so loose. It will be tough from that side, but we will have to manage it as well as we can.”
Second-placed Sami Pajari endured particularly heavy dust on his opening run and eventually improved to eighth, 4.3sec off Solberg.
“Quite an interesting shakedown for an exciting rally,” said Pajari. “There was a lot of dust and I hope it won’t be this bad in the rally, otherwise I will have no chance.
“It is going to be a very exciting rally. We will do the best we can. We still have some chances [in the title race]. We are looking forward.”
Nine-time champion Sébastien Ogier was fourth fastest, 1.8sec down, as he prepares for the final event of the Rally1 era.
“The story will be about the championship this time and I’m not part of [the battle],” he said. “We are here to enjoy this last race in Rally1.
“It is very loose and very dry and I expect a lot of hanging dust. Hopefully there will not be too many punctures.”
Adrien Fourmaux completed the top five, just 0.1sec behind Ogier, while returning M-Sport Ford driver Mārtiņš Sesks climbed to seventh on his fourth attempt after admitting he felt “quite rusty” following his absence since Finland.
Josh McErlean and Jon Armstrong completed the top 10, while newly crowned WRC2 champion Robert Virves was the fastest Rally2 runner with a 2min 38.4sec effort.
There was drama for Hyundai’s Dani Sordo, whose shakedown was interrupted by a heavy impact on his first run which left the left-rear suspension of his i20 N Rally1 badly damaged.
Competitive action begins later on Thursday with the 2.08km Ittiri Arena Show.