United was the only team with a mathematical chance of overhauling Pep Guardiola's side, but a line-up bearing 10 changes from the 3-1 victory at Aston Villa showed how realistic Ole Gunnar Solskjaer thought those hopes were.

Liverpool is at Old Trafford on Friday (AEST) for its rearranged game, and Solskjaer's youthful line-up for this second of three matches in five days fell behind when Luke Thomas brilliantly steered in a 10th-minute volley for his first Premier League goal.

Mason Greenwood extended his recent purple patch to eight goals in 11 outings shortly afterwards but United carried little threat and Leicester centre-back Soyuncu was left to make his most telling contribution at the other end of the field midway through the second half.

It meant a third title in four seasons for Manchester City – an outcome that felt slightly fanciful when it lost 5-2 at home to Leicester in September.

There was an injury scare for United left-back Alex Telles early on and Leicester's opener came as Youri Tielemans made progress down his flank, possibly over hitting the cross from which Thomas finished with aplomb.

A teenager more familiar with the scoresheet quickly got United back on terms, Greenwood drilling home in superbly assured fashion after Amad Diallo got the better of Thomas.

David De Gea pushed another awkwardly dipping Tielemans cross behind for a corner in the 28th minute, as the lively start to proceedings gave way to a more fragmented contest.

The Belgium midfielder remained the only Leicester player who looked frequently capable of unlocking a patched-up United and he slid a pass into Kelechi Iheanacho – De Gea sharply denying the striker with his boot.

Leicester's deliveries from open play left plenty to be desired, although Marc Albrighton's 66th-minute corner picked out Soyuncu to power home as substitute Marcus Rashford was caught napping.

Rashford, Edinson Cavani and Bruno Fernandes amounted to some particularly prolific cavalry, the latter slicing wastefully wide six minutes from time as City readied the champagne corks.