If you didn't watch the match, try to find the highlights (sadly, due to Olympic airing rights, the highlight reel I saw previously has been removed). Del Potro was back to good old US Open 2009 form and his forehand was painting all corners in his massive 7-6 7-6 upset of the world number one in the Rio Olympics.
Amazing match which definitely made this Olympic tennis tournament more interesting despite lack of some of the top players.
Since I can't find a good video to link to, here are some images. Well done Del Potro and commiserations to Djokovic who, frankly, deserves an Olympic medal. Maybe in doubles?