Admiral Muskwe's cool finish from 12 yards was added to by a brace from trialist Ali Reghba to seal a eighth league win of the season for the Foxes, who sit second in Division 1.
One change was made to City’s starting line-up following a 1-0 victory over leaders Everton last Monday as Lamine Kaba Sherif replaced Yohan Benalouane in South Wales.
There were six new faces in the Swans' side, meanwhile, as first team stars Luciano Narsingh and Declan John featured from the start for the hosts, who are bottom of the league standings.
Within the opening five minutes, City’s youngsters advanced swiftly down the left channel and Calvin Ughelumba found Muskwe in space.
However, the senior Zimbabwe international, who recently returned from a long-term injury, was unable to sufficiently get it out of his feet and arrowed it onto the top of the crossbar.
Another chance came their way midway through the first half as Callum Wright’s half-volley from the edge of the area was palmed away by Steven Benda in the Swans’ net.
Despite impressing, it looked like Leicester would go in at the break goalless – until a stunning late salvo saw them establish a two-goal advantage in just 120 seconds of play.
As the clock neared 45 minutes, a driving run from Reghba lured in Simon Paulet to make a rash challenge on the 19-year-old just inside the 18-yard box.
Up stepped Muskwe to fire past Benda. That seemed to be the final act, but Reghba doubled City’s lead in quick-fire fashion after galloping forwards from the restart and slotting into the bottom corner.
Leicester were in control in the second half as well and, with 66 minutes on the clock, Muskwe played in Reghba to add his second goal of the game in confident fashion inside the 18-yard box.
Who impressed?
Always an assured figure for the Foxes, left-back Calvin Ughelumba once again stood out as an attacking force for the visitors in South Wales.
The 19-year-old defender was often the spark in which City built attacks upon while he was also alert to the danger of counter-attacks when advancing forwards.
Where does it leave us?
Following Everton’s 2-0 success over 10-man Chelsea on Monday, the Foxes stay in second, one point behind the 2017 champions of Division 1 after 15 matches.
Coming up…
City’s youngsters next entertain Exeter City in the Premier League Cup group stage at Holmes Park on Wednesday (7pm GMT kick-off) – live and free on LCFC TV from 6:45pm GMT.
The details…
City: Johansson, Johnson (c), Knight, Pascanu, Ughelumba, Kaba Sherif, Dewsbury-Hall, Wright (Leshabela 81'), Shade (Tee 88'), Muskwe (Loft 81'), Reghba (trialist)
Subs not used: Bramley
Goals: Muskwe 45’ (p), Reghba 45’, 66'