Нападающий забил первый гол, а защитник не успел его остановить.

Нападающий originally comes from the present active participle of нападать (to attack), so literally it means something like attacking. In modern Russian, though, it is very commonly used as a noun meaning forward / attacker / striker, especially in sports.

Защитник is a regular noun built from защита (defense/protection) and means defender.

So in this sentence:

• нападающий = the attacker / forward
• защитник = the defender

Russian often uses adjective-like forms as nouns when the meaning is clear from context.

Забил is the past tense of the perfective verb забить. Perfective verbs usually focus on a completed action or a result.

Here, the result matters: the attacker scored a goal.

• забил = scored, got the goal in
• забивал = was scoring / used to score / scored repeatedly, depending on context

In this sentence, one completed event is being described, so забил is the natural choice.

Гол is the direct object of забил (scored), so it goes in the accusative case.

But гол is:

• masculine
• singular
• inanimate

For masculine inanimate nouns, the accusative singular is the same as the nominative singular. So:

• nominative: первый гол
• accusative: первый гол

That is why the form does not visibly change.

It means the first goal.

Depending on context, this could mean:

• the first goal of the match
• the first goal for that team
• the opening goal

Russian does not specify more than English does here. The exact meaning depends on the wider context.

А often connects two clauses while also showing contrast or a shift of focus.

Here:

• Нападающий забил первый гол = the attacker scored the first goal
• а защитник не успел его остановить = while/as for the defender, he did not manage to stop him

So а works well because it sets the defender’s action against the attacker’s action.

Rough comparison:

• и = and
• но = but
• а = and/but, with contrast or topic shift

In this sentence, а feels very natural because the two players are being contrasted.

Literally, it means did not manage to stop him in time or did not have time to stop him.

The verb успеть means:

• to manage to do something
• to be in time to do something

So:

• успел остановить = managed to stop
• не успел остановить = did not manage to stop / didn’t get there in time to stop

This is a very common Russian structure:

• успеть + infinitive
• не успеть + infinitive

Остановить is perfective, and it fits well after успел / не успел because the speaker is talking about whether one complete action was achieved.

• остановить = to stop completely, to succeed in stopping
• останавливать = to be stopping / to stop habitually / to attempt stopping in an ongoing sense

With не успел, Russian normally uses the infinitive that expresses the action as a whole:

• не успел его остановить = did not manage to stop him

That means the defender failed to achieve the result.

Его here means him, referring back to нападающий.

It is the accusative form of он for a masculine animate object:

• nominative: он = he
• accusative: его = him

The verb остановить takes a direct object, so the attacker appears in the accusative.

For masculine animate nouns and pronouns, the accusative often looks like the genitive. That is why you get его here.

Yes, it could:

• ...а защитник не успел остановить нападающего.

That is grammatically correct.

But using его is more natural and less repetitive, just like English prefers him instead of repeating the attacker.

In Russian, object pronouns often come before the infinitive:

• не успел его остановить

This is very natural word order.

You could also change the order in some contexts for emphasis, but this version is the standard neutral one. Russian word order is more flexible than English, but not random. Here the sentence flows naturally as:

• did not manage him to stop = did not manage to stop him

In Russian past tense, singular verbs agree in gender with the subject.

So:

• нападающий is masculine → забил
• защитник is masculine → успел

Compare:

• она забила = she scored
• он забил = he scored

The same applies to успел / успела.

Yes. The whole sentence describes two single completed events in a match:

• the attacker scored
• the defender did not manage to stop him

That is why the sentence uses perfective forms:

• забил
• успел
• остановить

This gives the sentence a clear, event-by-event feel. If you changed these to imperfective forms, the meaning would shift toward process, repetition, or background description rather than one concrete result.