Leicester City s French midfielder Nampalys Mendy (L) vies with Manchester City s Belgian midfielder Kevin De Bruyne (R) during the English Premier League football match between Leicester City and Manchester City at King Power Stadium in Leicester, central England on October 29, 2022. AFP
Guardiola's side were without Erling Haaland at the King Power Stadium after the Norwegian failed to recover from an ankle injury.
But, after a recent dip in form, De Bruyne ensured the prolific striker wasn't missed as he netted with a superb set-piece in the second half.
"He is back. He was not playing good in the last games but he was amazing," Guardiola said.
"He knows it. He's a player we need to be dynamic and free. But it is difficult with a back five and a holding midfielder because literally there is not the space."
City's first away win in their last four games moved them one point above second placed Arsenal, who host Nottingham Forest on Sunday.
Since their damaging loss at Liverpool, City have recovered with successive league victories to underline their determination to win a fifth title in six years.
"It is a massive victory for us. Leicester away is always complicated. We had to suffer," Guardiola said.
"It's a good result when you play early on Saturday and win. Now we wait to see what the rest are going to do."
Leicester's first defeat in four matches leaves them one place above the relegation zone.
Haaland had started all but one game this season after joining from Borussia Dortmund, scoring 22 goals in all competitions.
"He has ligament damage. He feels better, we have one more week," Guardiola said of Haaland.
"He won't play against Sevilla (in the Champions League next week) because we've already qualified and hopefully against Fulham he can help us. If not he might play against Chelsea in the League Cup."
Dazzling De Bruyne
With Haaland sidelined, Julian Alvarez came in for his second league start of the season and City seemed unfazed in a vibrant start.
Danny Ward had to save Ilkay Gundogan's header before De Bruyne whipped a corner towards Rodri, whose header was tipped over by the Leicester keeper.
Bernardo Silva was next to test Ward from just inside the penalty area as the City barrage gathered pace
Camped in their own half for long periods, it took Leicester 25 minutes to muster a shot, with Harvey Barnes' effort ending City keeper Ederson's spell as a spectator.
De Bruyne's long-range drive was too close to Ward, while Jack Grealish's penalty appeal was rejected after he tumbled theatrically under a challenge from Kiernan Dewsbury-Hall.
City kept up the pressure as Rodri blasted narrowly wide from distance early in the second half.
City had failed to score in their previous three away games, but De Bruyne finally ended that drought in the 49th minute.
Taking aim from 25 yards, the Belgian star unleashed a superb free-kick that curled around the Leicester wall as it flashed into the top corner via the post.
De Bruyne's 60th Premier League goal moved the Belgian into joint fourth place alongside David Silva in City's list of record scorers in the competition.
It was also City's first goal direct from a free-kick in the Premier League since January 2021
Youri Tielemans was inches away from an immediate equaliser for Leicester when the Belgian's ferocious drive was tipped onto the crossbar by Ederson.
Kelechi Iheanacho came off the bench and twice went close to a leveller with a snap-shot that whistled just wide and then a close-range effort straight at Ederson.
City almost contrived to gift Leicester a point in stoppage-time when John Stones' header hit Ruben Dias and flew narrowly wide.
(For more sports news and updates, follow Ahram Online Sports on Twitter at @AO_Sports and on Facebook at AhramOnlineSports.)