Alexander Zverev defeated Joao Fonseca 7–5, 6–7, 6–3 in the quarter-final of the Monte Carlo Masters on clay, confirming his status as pre-match favourite with odds of 1.6 to Fonseca's 2.3. The German navigated a competitive second set that went to a tie-break before establishing control in the decider to secure his place in the semi-finals. Zverev's victory reinforces his clay-court credentials at one of the ATP's most prestigious events, while Fonseca's loss halts what appeared to be a promising run at the principality's premier tournament.