(Based on the critical edition)
Sections in Tristubh shlokas
A. Vrishasena fight with Nakula. Arjuna kills Vrishasena. Karna enraged advances against Arjuna.
B. All beings take sides of either Karna or Arjuna. Brahma and Shiva predicts the victory of Arjuna. Ashwatthama's plea to Duryodhana to stop the battle.
C. The start of the battle. Karna gains early advantage. Both Bhima and Krishna criticize Arjuna.
D. Arjuna routs the Kaurava army around Karna, forcing them to flee.
E. Karna fixing the snake arrow and Shalya criticizing his bad aim. The arrow destroys the diadem that Arjuna wore.
F. Arjuna slaying Ashwasena on Krishna's instructions.
G. The fight continues with Both Karna and Arjuna wounding each other.
H. Arjuna severely wounds Karna and destroys his earrings, armour and crown.
I. Curses start to manifest. Karna's chariot starts to whirl around and his weapons no longer appeared.
J. Karna laments about Dharma. Arjuna's arrows dislogue Karna's horses and chariot. Karna censures Dharma repeatedly.
K. Krishna says that it's fortunate that Karna is now remembering Dharma, asking him where his Dharma was when Draupadi was brought to the sabha.
L. Arjuna strikes down Karna's standard.
M. Arjuna takes the Anjalika arrow for Karna's death and fires it.
N. Karna is beheaded. Kaurava army flees away.
Sections in Anustubh shlokas
A. Karna and Arjuna face each other and both armies cheer them on.
B. Shalya promises to kill Arjuna and Krishna if karna is slain. Krishna promises to slay Karna if Arjuna is killed.
C. Krishna pressing down the chariot wheel to save Arjuna from the snake arrow.
D. Karna gaining advantage over Arjuna towards the end, repelling all his weapons and even cutting his bowstring.
E. Arjuna taking up Raudrastra and Karna's chariot wheel getting stuck in the ground.
F. Karna's plea asking Arjuna to wait till he picks out the chariot wheel.
G. Krishna questioning karna about deceiving Yudhishtira in dice game and Duhshasana opressing Draupadi.
H. Further fight between Karna and Arjuna using Brahmastra, Agneya, Varuna and Vayavya.
I. Further descriptions of Karna's death.
One interesting detail that can be noticed here is that the Tristubh shlokas alone tell a complete story of the battle. This do make me wonder that it's likely that originally the entire fight was composed in Tristubh only with the Anustubh shlokas being a later addition.