The Olympic gold medallists from Rio 2016 triumphed in a thriller against Spain 4-3, while New Zealand came out on top of a tighter second contest, 2-1 against France.

The day’s opening match at the Kalinga Hockey Stadium was hectic from the very beginning as Argentina and Spain shared five goals between them in the first 15 minutes.

Spain’s Red Sticks took the lead twice through Enrique Gonzalez and Josep Romeu, only for Agustin Mazzili to equalise on both occasions.

Argentina, currently ranked second in the world, then took the lead when Gonzalo Peillat drag-flicked a penalty corner between Quico Cortes’ legs in the Spanish goal.

The second-quarter then came and went with no further goals, but Spain drew the scores level again in the third when Vincenc Ruiz fired a rebound into the roof of the net after a team-mate's initial shot hit the post.

Argentina’s win was sealed however, when Peillat finished another penalty corner.

Afterwards, their forward Lucas Vila said he was pleased with the win but acknowledged there was room for improvement.

"We needed to defend our circle better," Vila said.

"We tried to do it today but couldn’t do it in the best way, but at least we could score more than them."

The day’s second game was another close encounter but less thrilling.

The score remained 0-0 after the first-quarter, but the Black Sticks opened the scoring in the first minute of the second when Kane Russell scored from open play.

Four minutes from full-time, Stephen Jenness then doubled the lead with a nice finish from a tight angle, though the French did pull a goal back in the final minutes from a penalty corner.

Their captain Victor Charlet scored that.

Immediately following the match, South African umpire Peter Wright was presented with a golden whistle by FIH President Narinder Dhruv Batra to mark the 100th international match the official has covered.

Tomorrow the competition is due continue with Pool B action.

Reigning world champions Australia will face Ireland, before England take on China.