(Reuters) - Argentina needed an extra-time goal to overcome Switzerland in a nailbiting World Cup match on Tuesday but coach Alejandro Sabella congratulated his team on their tactical discipline and declared the win "well-deserved."

Angel Di Maria scored in the 118th minute to send Argentina through to a quarter-final against Belgium or the United States.

"It was a game that we deserved to win in 90 minutes," Sabella told reporters.

"It was even during a first half in which they had two clear chances to score, but in the second half we were clearly superior, we had five or six shots at goal and in extra time we also had more chances."

It was a fraught match which neither side was able to dominate, with Switzerland defending intelligently and shackling Argentine talisman Lionel Messi.

When Messi finally got some space to run at the Swiss defense he laid a perfect pass into the path of Di Maria who neatly stroked the ball home from just inside the box.

"Just a few minutes before the end there was this pass from the midfield to Messi and he was in a very advantageous position and a player like him getting the ball in an advantageous position can cause a lot of harm," Sabella said. "And there you go, he found Di Maria.

"It would seem he was running more and more (and) the more time went by the more he was on the attack. So we brought two players together and that's how we came up with the goal."

Sabella said discipline was a crucial factor and singled out two unsung heroes for their individual performances.

"Marcos Rojo had a wonderful match once again, a player that was highly debated," the coach said.

Goalkeeper Sergio "Romero played a wonderful match, people talked about him as well so I congratulate everyone who played in our team because of the effort they made.

"They never lost their balance and this is really important in these matches because that anxiety in wishing to win (can) lead you to open up spaces for the opponent."

One downside though was that Rojo got his second yellow card of the tournament and will miss the quarter-final.