Lautaro Martinez insists he was not feeling the pressure despite a goal drought that ended with his strike in Argentina's 4-1 Copa America win over Bolivia on Monday.

The win extended Lionel Scaloni's side's unbeaten run to 17 matches – the joint-third longest undefeated sequence in the country's history – yet Argentina came into the game having only scored three goals from as many Copa games.

Inter forward Martinez had drawn a blank in his past five games for Argentina, dating back to November's 2-0 World Cup qualifying win in Peru.

Martinez was back on the scoresheet against the bottom side in Group A, coming off the bench to strike in the 65th minute in a resounding win.

"I'm calm because the coaching staff and my team-mates trust me," Martinez told TyC Sports.

"The ball sometimes goes in and sometimes it doesn't. Strikers live by goals, but I stayed calm."

Argentina's victory sealed top spot in Group B, locking in a quarter-final date with Ecuador in Goiania on Saturday.

"We will face what comes next in the Copa in the best way; a tough opponent that we already know," Martinez said.

Lionel Messi produced a masterclass with two goals and an assist, making history as Argentina's most capped player in style as he surpassed former team-mate Javier Mascherano's tally with his 148th international cap.

It was Messi's first brace for Argentina in 18 games, dating back to August 2019. The 34-year-old also recorded his second two-goal outing in a Copa fixture.

Martinez added: "I am happy with the team's work, we are growing. Bolivia was already eliminated and we took the game on seriously and responsibly. Every time you play with Argentina you have to go in with everything to win."

Argentina head coach Scaloni said he has the "utmost respect" for Ecuador and would not be drawn on his likely line-up for the game.

"I would be lying if I said who is going to play on Saturday against Ecuador," he said.

Scaloni did clarify defender Cristian Romero was left out against Bolivia as he manages his squad ahead of the Ecuador game, not due to a fresh injury.

"There is no need to worry about Cristian," he said. "He was left off the bench because very difficult games are coming and the idea is that everyone needs minutes."

He added: "We have the utmost respect for Ecuador. They have shown that they are a good team, young, dynamic, with good players and are going to fight."