Hector Herrera (R) of Porto vies with Carraca of Boavista during the Portuguese League soccer match between Boavista and FC Porto at Bessa Stadium in Porto, Portugal, on Dec. 2, 2018. FC Porto won 1-0. (Xinhua/Catarina)

　　Felipe (C) of Porto vies with Idris (L) of Boavista during the Portuguese League soccer match between Boavista and FC Porto at Bessa Stadium in Porto, Portugal, on Dec. 2, 2018. FC Porto won 1-0. (Xinhua/Catarina)

　　Players of FC Porto celebrate scoring during the Portuguese League soccer match between Boavista and FC Porto at Bessa Stadium in Porto, Portugal, on Dec. 2, 2018. FC Porto won 1-0. (Xinhua/Catarina)

　　Otavio of Porto competes during the Portuguese League soccer match between Boavista and FC Porto at Bessa Stadium in Porto, Portugal, on Dec. 2, 2018. FC Porto won 1-0. (Xinhua/Catarina)

　　Danilo Pereira (C) of Porto vies with Rafael Lopes (R) of Boavista during the Portuguese League soccer match between Boavista and FC Porto at Bessa Stadium in Porto, Portugal, on Dec. 2, 2018. FC Porto won 1-0. (Xinhua/Catarina)

　　Hernani of FC Porto celebrates scoring during the Portuguese League soccer match between Boavista and FC Porto at Bessa Stadium in Porto, Portugal, on Dec. 2, 2018. FC Porto won 1-0. (Xinhua/Catarina)

　　Head Coach Sergio Conceicao of Porto gestures during the Portuguese League soccer match between Boavista and FC Porto at Bessa Stadium in Porto, Portugal, on Dec. 2, 2018. FC Porto won 1-0. (Xinhua/Catarina)

　　Hernani (C) of FC Porto celebrates scoring during the Portuguese League soccer match between Boavista and FC Porto at Bessa Stadium in Porto, Portugal, on Dec. 2, 2018. FC Porto won 1-0. (Xinhua/Catarina)