Lionel Messi got the better of Cristiano Ronaldo in their first international meeting on Wednesday, scoring a 90th-minute penalty to give Argentina a 2-1 win in a friendly.
Two-time world player of the year Messi also exerted his influence early playing as a central striker, and set up Angel di Maria to give Argentina a 14th-minute lead.
"I've played in the same position for Barcelona and I've been very comfortable because I get more of the ball," Messi said. "We knew it was going to be a tough game because Portugal have very quick players."
Ronaldo leveled in the 21st minute to get his first goal in a match against Messi, after facing Barcelona six times for Manchester United and Real Madrid.
The Portugal captain, who preceded Messi as the world's best player in 2008, also went close twice with second-half shots.
"The draw would have been fair. We played well. In the first half we dominated after Argentina had also dominated," said Ronaldo, who has 26 goals in 80 international appearances. "We're keeping our heads high."
Portugal seemed certain to take the lead in the 56th minute, but striker Hugo Almeida was guilty of a glaring miss from two yards (meters).
Argentina substitute Javier Pastore struck the crossbar with an 86th-minute header.
Messi and Ronaldo have been regular opponents at club level, but their two countries had last played each other in 1972.
"We always enjoy seeing two great players on the same field," Argentina coach Sergio Batista said. "I liked both of them tonight. Lionel was at a higher level."
Both teams showed positive signs in their rebuilding process - under Batista and Portugal coach Paulo Bento - after underachieving at the World Cup in South Africa.
"We're faithful to our way of playing but we know we have a still a lot of improving to do," Messi said.
The neutral Stade de Geneve felt like a home game for Portugal thanks to its large expatriate community in the French-speaking part of Switzerland.
Messi was therefore subjected to whistles and jeers when he shimmied past a Ronaldo challenge in the 2nd minute.
The tiny Argentine had the first effort at goal in the 7th, heading wide from eight yards (meters).
Messi then danced over a wild tackle by Raul Meireles before chipping an angled pass for Real Madrid winger Di Maria to deftly guide his shot over the advancing goalkeeper Eduardo.
Argentina goalkeeper Sergio Romero dealt uncertainly with a cross in the 19th minute, and was beaten in Portugal's next attack.
Ronaldo moved decisively on to Hugo Almeida's flicked header, making Romero seem hesitant as he slid in to strike a powerful rising shot into the net from six yards (meters).
Ronaldo threatened again in the 24th; counterattacking from an Argentina corner but his shot was deflected just wide.
Newly energized, the Portugal captain did double duty in defense when fouling Messi in the center circle to stop an Argentina break.
Messi earned another free kick in the 34th, but his shot from 20 yards (meters) was charged down by the Portugal wall.
Argentina wasted a clear chance in the 40th, when Ezequiel Lavezzi fired a first-time shot over the bar from Marcos Rojo's left-flank cross.
After the break, Ronaldo's half-volley rose too sharply over the goal when Romero was again unconvincing in the goalmouth.
When played onside in the 56th, Ronaldo had time to place a right-foot shot which the diving Romero parried into Almeida's path.
The big striker was clear in front of goal but prodded the ball wide, raising howls of frustration from Portuguese fans.
Ronaldo departed after an hour as coach Bento changed his entire three-man forward line.
Messi stayed on as Di Maria made way for Pastore, and the replacement was sent clear by Messi but substitute goalkeeper Rui Patricio smothered the shot.
Honors seemed sure to be even until referee Massimo Busacca awarded a penalty against defender Fabio Coentrao in a tangled challenge.
Messi approached the spot-kick with a lazy run and deceived the 'keeper into diving the wrong way. It was the 23-year-old's 16th goal in 54 internationals.