riddle - Tartar sauce, Gary!

My pet underwater snail just chewed up this poem I've been working on! I convinced him to spit it out, but I could only salvage one verse (you know how long I like to make my poems) and the lines are in the wrong order.

Can you put them in the proper order and find out what's going on in this stanza? It rhymes now, but it might not when correctly reconstructed.

What a certain literary professor for his unbeheld felt,
The two of spades, from a new deck dealt,
A din, a doubt...
Out!
Up, up, by the Ort Sphere's smallest test,

But oh, wait, now by one-third less.

Partial answers are welcomed, but for one to be accepted it must explain each line.

HINTS:

GIVEAWAY: He, name redacted (1289-1316), was the first real player.

Line 1: \u0412\u043b\u0430\u0434\u0438\u0301\u043c\u0438\u0440 \u0412\u043b\u0430\u0434\u0438\u0301\u043c\u0438\u0440\u043e\u0432\u0438\u0447 \u041d\u0430\u0431\u043e\u0301\u043a\u043e\u0432

Line 1: Unbeheld, prefix-less and in the first person present rendered, succeeds the unbeheld and "and".

Line 1: _ _ _ _ ( -> _ _ _ ) [4 letter word sometimes abbreviated as 3]

Line 2: The suit is irrelevant; it is without currency.

Line 2: _ _ _ _ _ [5 letter word]

Line 3: Mrs. Malaprop would definitely know this one.

Line 5: What is truth? It is the man who stands before you.

Line 5: Find the man whose name is like a rabbit. Yes! The man, the one with a mathematical habit.

Line 5: _ _ [2 digit number]

Line 6: _ _ [2 digit number]

You're confused, you say? Well, that's a great point.

All the lines together (in the proper order) describe something very specific, but each separate line might represent something distinct on its own.

The wordplay tag should provide some direction with the foreign-seeming elements.

Answer

Got it!

What a certain literary professor for his unbeheld felt: LOVE (deciphered in other comments); in tennis, "love" means 0.
The two of spades, from a new deck dealt: DEUCE. (Both the name for the card and a name for someone who deals the second card instead of the first to cheat.) A deuce is a tied 40-40 game in tennis.
A din, a doubt: AD IN, AD OUT are tennis terms. When the score is tied at 40-40, a player must win two points in a row to win the game. AD IN and AD OUT are terms meaning the IN or OUT players have one of those points - AD stands for 'advantage'.
Out!: Game over, OUT won.
Up, up, by the Ort Sphere's smallest test, : Up, up refers to two points being gained; therefore the score is 30. Peter Shor's algorithm was first used to test factorization of 15.
But oh, wait, now by one-third less.: The score in tennis goes from 0 to 15 to 30 to 40 (it was an abbreviation for 45); this means the increase is one-third less, as it only goes up by 10 instead of 15. So now the score is at FORTY.

So the order is:

What a certain literary professor for his unbeheld felt: LOVE

Up, up, by the Ort Sphere's smallest test, : FIFTEEN, THIRTY
But oh, wait, now by one-third less.: FORTY
The two of spades, from a new deck dealt: DEUCE.
A din, a doubt: AD IN, AD OUT (the players are switching back and forth between having a deuce and giving one person the advantage).
Out!: Out wins!