Is a two-rak'ah prayer interrupted for someone who enters the mosque on Friday while the imam is delivering the sermon?

If you catch one unit (rak'ah) of the prayer with its two prostrations, then complete your prayer lightly, based on the hadith: "Whoever catches one rak'ah of the prayer has caught the prayer." However, if the preacher begins the sermon before you complete one rak'ah with its two prostrations, then cut off your prayer, due to the obligation of listening to the sermon.