After being deadlocked for more than 55 minutes, Princeton broke through first when Sanner recovered a ball sent in off a corner kick by Joe Saitta and headed down by Mark Linville, knocking it past Lehigh goalkeeper Ciaran Nugent in the 58th minute.
Less than five minutes later, Porter added to it when he corralled a Linville throw-in and beat Nugent. Moments later, the Mountain Hawks (7-4-5) switched to Taylor Sulmonetti in goal, who closed out the game without allowing Princeton to add to the lead.
Though the teams have played eight times since then, it was the first time in the Lehigh-Princeton series since 1993 in which the game was decided by more than one goal.
Tiger goalkeeper Seth MacMillan recorded the clean-sheet win as Princeton outshot Lehigh 13-8 on the night.
Now standing at 5-8-2 on the season, Princeton will head to Penn Saturday night for its final road game of the fall before closing out the campaign on Nov. 12 at Roberts Stadium against Yale.