With this result, City rise to fourth in the Premier League table on 58 points from 33 matches, four points clear of both Chelsea and Aston Villa, albeit having played one more game. As the league stands, the top five teams are set to qualify for next season's Champions League, making this win particularly pivotal in the closing stages of the campaign.
The match remained goalless for the majority of the 90 minutes, as City struggled to break down a determined Everton side in a tense and competitive encounter. The breakthrough finally came in the 85th minute when O'Reilly converted a low cross from Matheus Nunes from close range. Kovacic then sealed the victory shortly after with a powerful strike from the edge of the penalty area.
Everton, currently 13th in the standings with 38 points, offered moments of promise, particularly in the first half. Defender James Tarkowski struck the post with a header from a corner, while Kevin De Bruyne was denied by a goal-line clearance from Jake O'Brien. Early in the second half, goalkeeper Stefan Ortega was called into action with a superb point-blank save to keep out a Jarrad Branthwaite header.
However, the hosts suffered a significant setback when Tarkowski, who had played every Premier League match since joining the club - a run of 109 consecutive appearances - was forced off through injury in the 52nd minute. From that point, City gradually asserted greater control.
Despite a brief scare when substitute Michael Keane misjudged a header back toward Jordan Pickford, allowing Omar Marmoush a chance that the goalkeeper ultimately smothered, Everton's attacking threat waned. Once O'Reilly broke the deadlock, the momentum firmly shifted in the visitors' favor.
For Guardiola, the victory brings welcome relief amid a closely contested top-four race. For Everton, under manager David Moyes, it was another performance full of effort and organization but lacking the clinical edge in the final third that continues to hinder their progress.
The match was one of the final Premier League fixtures to be played at the historic Goodison Park, as Everton prepare to relocate to their new stadium on the banks of the River Mersey.