Pep Guardiola's side, who had been out of sorts in the first half, showed their trademark resilience to keep alive their hopes of silverware this season.
Bournemouth, managed by Andoni Iraola, made the perfect start on their home turf. They capitalized on a glaring mistake from Matheus Nunes, whose sloppy pass across midfield gifted possession to the Cherries. Justin Kluivert's strike was bundled in by Evanilson to give the hosts a shock 1-0 lead.
City had already endured a frustrating first half. Erling Haaland, usually deadly from the penalty spot, saw his attempt saved by Kepa Arrizabalaga, and the Norwegian striker was denied again in a one-on-one situation when he raced through on goal.
The Cherries, playing with high intensity and tempo, fully deserved their lead at the break. However, Guardiola made a key tactical change at halftime, bringing on Nico O'Reilly to bolster the left wing. The impact was instant.
O'Reilly, full of energy and purpose, surged forward and teed up Haaland for his 30th goal of the season, bringing City level. But Haaland's evening took a turn when he twisted his ankle following a challenge from Bournemouth's Adam Cook, leading to a painful collision with the advertising hoardings.
Enter Omar Marmoush, who wasted no time in making his mark. The substitute found the back of the net just two minutes after coming on, curling a low shot past Kepa to give City a 2-1 lead. It was a goal the goalkeeper would surely want back, but it was a sign of the clinical nature City could exhibit even when not at their best.
From that point on, it was all Manchester City. The visitors controlled possession with typical composure, suffocating Bournemouth's attacks and ensuring they would hold onto their advantage. Seven minutes of stoppage time came and went, but the Cherries couldn't muster a response, failing to register a single shot on goal after halftime.
The result marked a record seventh consecutive FA Cup semi-final for City, an impressive achievement that underscores their continued dominance in the competition. Despite a season that has been far from perfect, Guardiola's side are still firmly in contention to salvage a trophy.
After the match, Guardiola was quick to praise his team's determination and depth. "Seven semi-finals in a row is an outstanding achievement," he said. "It speaks to the consistency of this group. At halftime, I told the players that the game was still in our hands, even though we weren't ahead. Nico's impact was huge, and the veteran playersâBernardo Silva, Ilkay Gundogan, and Kevin De Bruyneâalso played important roles."
Guardiola reserved particular praise for O'Reilly, who has been impressing in recent weeks. "Nico scored twice against Plymouth, and today he was outstanding. He will definitely play in the semi-final," the City boss added.
Bournemouth, who are still without a win in six matches, simply ran out of gas, and the game ended with a familiar City swagger. Now, all eyes will be on Wembley as Manchester City look to add another FA Cup to their collection.