It's about 1 3/4 miles between the two - how about a rather swift walk! Maybe just leave the Benfica game 5 mins from the end if you see that the score wont change, and you will be one the first to leave the stadium, jump on a taxi to Alvalade stadium which is not that far, just over a mile.

Shared stadiums\n\n As of the current 2024 season, two sets of teams share a stadium the New York Giants and New York Jets with MetLife Stadium, and the Los Angeles Chargers and Los Angeles Rams with SoFi Stadium meaning there are only 29 full-time NFL stadiums.