Στο τέλος του αγώνα, το δύο δύο ήταν καλό αποτέλεσμα.

Because Στο is the contraction of σε + το.

• σε = in / at / to
• το = the (neuter singular)

So:

• σε το τέλος → στο τέλος

This contraction is very common in Greek. It is capitalized here only because it is the first word of the sentence.

Στο τέλος is a very common expression meaning at the end.

Grammatically:

• σε normally takes the accusative
• τέλος is a neuter noun
• the accusative singular of many neuter nouns looks the same as the nominative

So στο τέλος literally means at the end.

Because του αγώνα means of the match.

The noun αγώνας means match / game / contest. After τέλος in the sense of the end of..., Greek uses the genitive:

• το τέλος του αγώνα = the end of the match

So του is the genitive singular article, and αγώνα is the genitive singular form here.

In Greek, a score can be treated like a noun phrase, and it is very common to put the neuter article το before it.

So:

• το δύο δύο = the 2–2 / the two-two score

The whole expression functions as one neuter singular subject in the sentence.

You will also hear similar patterns such as:

• το ένα μηδέν
• το δύο ένα
• το μηδέν μηδέν

Because scores in Greek are normally said as two numbers one after the other, without και.

So:

• 2–2 = δύο δύο
• 1–0 = ένα μηδέν
• 3–1 = τρία ένα

Using και would sound unnatural for a football score.

Because the subject is the whole expression το δύο δύο, which is treated as one singular neuter thing: the 2–2 result.

So Greek uses singular ήταν = was, not a plural verb.

Because αποτέλεσμα is a neuter singular noun, and the adjective has to agree with it.

• καλό = neuter singular
• αποτέλεσμα = neuter singular

So:

• καλό αποτέλεσμα = a good result

If the noun were masculine or feminine, the adjective would change too.

Because here Greek is talking about a good result, not the good result.

So:

• καλό αποτέλεσμα = a good result
• το καλό αποτέλεσμα = the good result

Greek often omits the indefinite article because Modern Greek does not have a separate word for a/an the way English does.

Yes. Greek word order is fairly flexible.

This sentence starts with Στο τέλος του αγώνα to set the scene first: At the end of the match...

You could also say:

• Το δύο δύο ήταν καλό αποτέλεσμα στο τέλος του αγώνα.

But the original version sounds natural because the time/context phrase comes first.

Not by grammar alone. Αγώνας can mean match, game, contest, or even struggle, depending on context.

In this sentence, because of the score δύο δύο, the natural interpretation is a sports match, very likely football/soccer.

Very often Greeks would write it as:

• Στο τέλος του αγώνα, το 2-2 ήταν καλό αποτέλεσμα.

That is completely natural in writing. When spoken, it would still be read as το δύο δύο.

It is pronounced as two separate words:

• δύο δύο

A learner should avoid trying to merge them into one word. Each δύο keeps its own stress.

So it sounds like:

• THEE-o THEE-o (roughly)

And with the article:

• το δύο δύο

The article is unstressed, while each δύο is stressed on the first syllable.