The Barcelona attacker admitted that he was getting "nervous" as the game edged ever closer to penalties, but is delighted that they have now booked their spot in the quarter-finals.
"I was nervous towards the end because we couldn't score and any mistake could have knocked us out," Messi told reporters.
"The minutes were passing by and we didn't want the match to go to penalties. We were suffering, but we had a special play, I passed to Angel and now we can celebrate."
Messi has scored four goals in four matches in the World Cup so far.