How to counter Pantheon
Let us take a look on how to beat Pantheon. We will look at champions who are strong against Pantheon and who are weak against Pantheon. Use win rate, gold difference and creep score difference at minute 10 to find the best 
Support champion who counters Pantheon. You can already win in champion select with the right counters for Pantheon. If you want to know how to counter Pantheon then you need to take into account the best picks vs Pantheon and the worst picks vs Pantheon. This Pantheon counter data is based on matches played by Pros on patch 15.1 and previous ones. It is important to see whether Pros counter picked Pantheon or whether they played as Pantheon.
Champions used by Pros to counter pick Pantheon
Looking at the matches from Pros (see table Pros counter picked Pantheon) we can see that they picked 
Pyke most often to counter pick Pantheon. The matchup Pyke vs Pantheon occured 5 times. Pantheon has 2 wins and 3 losses in this matchup. Learn how to counter pick Pyke to get another perspective on the data.
Lane outcome for Pantheon
When looking at Pantheon counters you will notice that win rates alone are not conclusional. Therefore we provide an overview (see table Lane Outcome) where you can see the lane outcome of Pros who played Pantheon. The lane outcome of Pantheon consists of three outcomes: Win, Loss or Draw. Let's take a look of Pantheon lane and match outcome for specific matchups. Considering the lane outcome and the match outcome of a specific matchup, might enable you to find the right counter for Pantheon.
Conclusion
Analyze the available data and learn how to beat Pantheon. To master Pantheon take also a look on Pantheon builds and runes for Pantheon. Good luck, Summoner!