Jamie Vardy and Harvey Barnes found the net for City inside the opening 18 minutes in Lancashire, before Ali McCann's deficit-halving strike in the second half, but it was the visitors who emerged with the victory in their fifth outing of pre-season.
After one Foxes squad sealed a 3-1 win at Derby County earlier in the day, manager Brendan Rodgers deployed another strong XI in the North West, with captain Kasper Schmeichel's maiden appearance of the summer among the team-news headlines.
On 11 minutes, Wesley Fofana's defensive header was the starting point of the move which led to their opener. Midfield general Kiernan Dewsbury-Hall soon took over, outmuscling Alan Browne, then threading a through-ball into Leicester's No.9, lurking on the edge of Preston's 18-yard box.
It was vintage Vardy, too, as the 35-year-old calmly stroked the ball beyond Freddie Woodman. A characteristically playful goal celebration followed.
Leicester were dominating the early proceedings against Ryan Lowe's Sky Bet Championship side. Perhaps out of frustration, Ryan Ledson earned an early yellow card – a rarity in pre-season – for a late challenge on James Maddison. City, though, remained composed and quickly doubled their lead.
Dewsbury-Hall, again, was in the thick of the build-up. It was his smart pirouette which evaded Bambo Diaby on the flank, before skidding a perfectly-weighted pass into Barnes. There was still plenty to do for City's No.7, who sheltered it assuredly and finished well for his third goal of the summer.
Rodgers' men were on control, holding the lion's share of possession for the entirely of the first half. There were chances for more goals as well. Ricardo Pereira's cross was headed wide of the post by Vardy. Albrighton then blazed over after Vardy ferried Barnes' low ball into his path.
An otherworldly first touch from Maddison later bought the No.10 time in the area, with only the ankles of Liam Lindsay preventing his low drive from testing Woodman. Ledson's block also kept the score down, as Barnes stuck a boot onto Albrighton's fizzed delivery across the Lilywhites' goalmouth.
Preston, who start their eighth consecutive second-tier campaign with a visit to Wigan Athletic next weekend, found another gear early in the second half. And the arrears were cut in half within five minutes of the restart as Andrew Hughes' floated cross was nodded past Schmeichel by McCann.
City were unlucky not to notch a third on 52 minutes. Newly-capped England international James Justin slipped the ball into Barnes, who darted past Lindsay on the byline, cutting it back into the six-yard box. Woodman, though, got there first before Vardy could pull the trigger.
Shortly afterwards, on the hour-mark, the ball grazed Fofana's forehead following superb wing-play from the evergreen Albrighton. Daniel Iversen, Preston's Player of the Season at the end of his loan spell from City last term, was then introduced to rapturous applause, replacing Schmeichel in the net.
Ayoze Pérez, on the other hand, was also brought on, with Albrighton the man to make way. Both sides will have felt aggrieved not to find the net soon after as Preston substitute Jordan Storey's powerful drive was instinctively clawed out of the near post by Iversen.
Rodgers' Premier League visitors countered, with flowing one-touch football involving Justin, Dewsbury-Hall and then Vardy, who hit a first-time effort over the bar. They got even closer when Maddison cut through the Preston defence and located Barnes. He could only find the base of the post, though.
That could have cost City had the linesman not raised his flag when Emil Riis Jakobsen – the hosts' top scorer last season – placed a loose ball past Iversen. While Leicester's attacking play impressed throughout, the latter stages offered a pre-season test of their defensive mettle too.
With Lowe's home side intent on rescuing a positive result just one week out from the outset of their league campaign, the Foxes' backline had to stand up. The competitiveness of the clash also showed as Storey, Benjamin Whiteman and Ched Evans all earned cautions in the final half an hour.
With the entirety of Leicester's back four playing the full 90 in Preston, it was a challenge they met. It could have been better, as Barnes fired straight at Woodman inside added time, but City nevertheless made it two wins from two on Saturday. Just a fortnight to go until the new Premier League season.
Major moment – Classic Vardy in Lancashire
The sight of Jamie Vardy pouncing onto a through ball and bulging the net has been a frequent spectacle for the Blue Army over past seasons. To see the 35-year-old's potency on show in pre-season will be particularly exciting for the Foxes faithful ahead of the new campaign.
Coming up – Sevilla visit Filbert Way
It's an exciting finale to Leicester City's pre-season campaign as Spanish side Sevilla visit King Power Stadium for a 6pm kick-off next Sunday. Tickets for that clash remain on general sale, HERE. Brentford are then the visitors on day one in the Premier League on Sunday 7 August (2pm kick-off).
All times BST.