Romelu Lukaku came on as a substitute and scored the only goal as Inter Milan beat 10-man Porto in the first leg of their Champions League last-16 tie.
The Belgian striker, who came on for Edin Dzeko in the 58th minute, struck in a rebound after his first effort had bounced off the woodwork in the 86th minute at the San Siro.
In a game riddled with missed chances, Porto had a double chance at 0-0, with Inter goalkeeper Andre Onana denying both Zaidu Sanusi and Mehdi Taremi.
The visitors then had Otavio sent off in the 78th minute for two bookable offences and could not keep Inter out.
The second leg takes place at Porto’s Estadio do Dragao on Tuesday, 14 March.