Ryan Giggs believes Wales' youngsters passed a major examination in getting their Euro 2020 qualifying campaign off to a winning start.

Daniel James' fifth-minute strike gave Wales a 1-0 victory over Slovakia in Cardiff, and the confident Dragons might have added to their lead before the interval.

But Wales, who had seven players with fewer than 10 caps in the starting line-up, had to withstand late pressure before securing three points at the Cardiff City Stadium.

"We are going to learn from that because we were put under pressure at the end," said Wales manager Giggs.

"I challenged the players to keep more clean sheets because we feel with our attacking talent we are going to create chances.

"We are going to score goals. It's going to make it more important that we do keep clean sheets."

Swansea winger James was making his first competitive start for Wales, the 21-year-old having previously played only 56 minutes in the friendly defeat to Albania in November.

But James has established a growing reputation in the Sky Bet Championship this season and is drawing admiring glances from the Premier League.

Wales profited from their first attack when James caught Peter Pekarik napping on the edge of the Slovakia penalty area and drilled his shot past goalkeeper Martin Dubravka.

"He's brought his club form onto the international stage," Giggs said.

"I'm delighted because his overall game was fantastic, and to top it with a goal was great.

"He was just a threat all day, he will be with that pace but he's got much more as well.

"He can go either side, he's intelligent and he works hard. I am delighted for him that he got the winner."

Wales are the only unbeaten side in Group E after Croatia's surprise 2-1 defeat to Hungary in Budapest.

Croatia, Hungary and Slovakia have won one and lost one in the opening round of matches.

Azerbaijan lost their opening game and Wales next face a June double-header away to Croatia and Hungary.

"There was a bit of pressure on us," Giggs said.

"I tried to play it down beforehand, but you can't hide from the fact that the other teams had played and Croatia and Slovakia had got three points.

"We have two away games in June and a camp in May to bridge that gap.

"We didn't want a month without football and during that camp in May we will be able to work on stuff."