It was a dream Boca Juniors debut for Alexis Mac Allister in Curitiba as the Brighton loanee struck a wonderful late winner to hand his new club a vital away win over Athletico Paranaense in the first leg of their Copa Libertadores last 16 clash.

The Brazilian club swept past Boca in the group stages with Marco Ruben scoring a hat-trick that night but the Argentine striker, so deadly in this year’s competition, spurned a glorious opportunity to salvage a draw in stoppage time when his penalty came back off the post.

There was little between the two sides with Athletico restricted largely to efforts from distance and Ramón Ábila wasting a one-on-one chance for Boca during the tense first half.

It had looked as though the pragmatic Gustavo Alfaro would accept the stalemate in the knowledge that Athletico have proved to be poor travellers in continental competition but in the 83rd minute, Mac Allister exchanged passes with substitute Carlos Tevez 25 yards out and fired a shot with the help of a slight deflection into the top corner.

With the away goal in hand Boca were holding on the victory but a mix-up between Emmanuel Mas and Esteban Andrada saw the pacy Rony steal in behind and draw a collision that prompted a VAR review. Referee Daniel Fedorczuk pointed to the spot deep in stoppage time and Ruben, who has already scored four goals against Boca in this year’s Libertadores saw his effort send Andrada the wrong way but clatter against the post.

Boca have won every game in La Bombonera including a 2-1 win over Athletico to take top spot in the group and will now be firm favourites for a place in the quarter-finals.

Athletico Paranaense  0 – 1  Boca Juniors

🎥👏 ¡Las mejores imágenes de la victoria de @BocaJrsOficial en Brasil frente a @AthleticoPR!@FutbolSantander pic.twitter.com/sHVAP6kwgh

— CONMEBOL Libertadores (@Libertadores) July 25, 2019

Earlier in Bajo Flores, San Lorenzo were unable to find a way past Cerro Porteño and could be left to rue their inability to take an advantage to Asunción next week.

Even after the Paraguayans had Alberto Espínola sent off for a studs up challenge on Héctor Fértoli shortly after the hour mark, San Lorenzo couldn’t fashion a clear chance.

Fernando Belluschi back in the side under new manager Juan Antonio Pizzi threatened from range on occasion but new striker Adam Bareiro or substitutes Nicolás Reniero and Nicolás Blandi didn’t see many sights on goal from inside the penalty area.

It could have been worse for San Lorenzo but for a superb goalline clearance by captain Fabricio Coloccini denied Cerro Porteño a certain goal in the counter.

San Lorenzo  0 – 0  Cerro Porteño

🎥👀 Empate sin goles entre @SanLorenzo y @CCP1912oficial: lo mejor del partido de ida de los octavos de final

🏆 #Libertadores @FutbolSantander pic.twitter.com/yL5ESFRVa0

— CONMEBOL Libertadores (@Libertadores) July 25, 2019