The 20-year-old opened the scoring in a 7-0 rout, after taking a pass from Anderlecht's Joshua Zirkzee. This afternoon's appearance in Victoria Stadium, Gibraltar, was his first start for the Under 21s and he has now represented his country at every age group from Under 16s upwards.
Victory made it 13 points from five European Championship qualifications for Erwin van de Looi's youngsters and he was pleased with Summerville and fellow new faces Wouter Burger, of FC Basel, and Wolfsburg's Micky van de Ven.
The trio are helping to keep more established players on their toes, says van de Looi.
"I look back on the first months with this group with a good feeling," he said.
"You can see that a number of players are developing well and we are also getting stronger across the board. This time we had Wouter Burger, Crycencio Summerville and Micky van de Ven. three new guys. They left a good impression on me. This means that the players who were there at the start are also put on edge."
Other goals in the win came from Zirkzee (2), Wolves defender Ki-Jana Hoever, RB Leipzig's Brian Brobbey and Hertha BSC duo Jurgen Ekkelenkamp and Daishawn Redan.
Summerville has enjoyed a bright start to the 2021/22 campaign, his second as a Leeds United player since signing from Feyenoord.
He shone for Mark Jackon's Under 23s last season with six goals and six assists in Premier League 2 action, without making a senior breakthrough.
An impressive pre-season and the departure of Helder Costa has put him squarely in the first team picture however. Since a Premier League debut away at Newcastle United as a substitute, Summerville has come off the bench against West Ham United, Southampton and Wolves. The latter was arguably his brightest display for Bielsa's side.
He has also featured in the Carabao Cup against Arsenal and Fulham and scored twice in seven Premier League 2 outings.