Why were Argentina's goals disallowed?

Argentina's World Cup opener got off to a disastrous start as they were bested 2-1 by minnows Saudi Arabia on Tuesday.

Lionel Messi's penalty set the game off to a perfect start for Argentina, who actually had the ball in the back of the net a further three times in the first half. Messi thought he scored another and Lautaro Martinez could have had two, but they were all chalked off for offside.

Let's take a closer look at what happened.

1. Lionel Messi

Messi thought he had his second goal ten minutes later as he drove through on goal and slotted home, only for the offside flag to go up.

Saudi Arabia's high line had caught Messi out and the fourth official correctly saw the PSG forward had strayed too early.

The automated offside technology confirmed the decision after a matter of seconds.

2. Lautaro Martinez

Martinez was called up for the tightest of offside calls as his delightful dink was ruled out.

Leaning in front of the last defender, Martinez wasn't actually called up by the fourth official but the automated offside technology made a quick decision on the Argentine because of the T-Shirt line rule.

The t-shirt line is understood to be three inches below the shoulder, above which players can still score goals. Because that area of Martinez's arm was beyond the defender, it was chalked off.

3. Lautaro Martinez

The easiest decision of them all was this second effort from Martinez.

Running on to Messi's pass on the left wing, the Saudi back line stepped up perfectly and Martinez was left well offside.

He finished well, but the offside flag was soon raised.