Arsenal and Manchester United both relied on a teenager to get their Europa League campaigns off to a winning start on Thursday.

Arsenal, last year’s finalist, saw 18-year-old winger Bukayo Saka score one goal and set up the other two in a 3-0 away victory over 10-man Eintracht Frankfurt. And 17-year-old Mason Greenwood became United’s youngest ever scorer in European competition when he netted the loan goal in a 1-0 home victory over Astana.

Arsenal manager Unai Emery started a trio of academy graduates, with Emile Smith Rowe, Saka and Joe Willock forming a youthful attack together with Aubameyang. It was the 20-year old Willock who opened the scoring in the 38th with a deflected right-foot shot from inside the area, which bounced off the crossbar and into the net.

Frankfurt chased an equalizer before midfielder Dominik Kohr was ejected 11 minutes from time after picking his second yellow card for a tackle on Saka.

The 18-year-old Saka — who like Smith Rowe was making his first start of the season — doubled the lead with a precise left-footer from outside the area in the 85th before setting up Pierre-Emerick Aubameyang to finish it off couple minutes later.

Standard Liege started with a 2-0 win over Vitoria in the other Group F game.

At Old Trafford, Ole Gunnar Solskjaer’s youth also impressed but the manager had to wait till the 73rd minute for Greenwood to score with a shot between the legs of Astana goalkeeper Nenad Eric. Two 19-year-olds, Angel Gomes and Tahith Chong, also started for United.

The three-time European champions are back in the second-tier competition after finishing sixth in the Premier League last season.

Rarely used midfielder Fred was also given his first start of the season and hit the bar three minutes into the Group L game.

Sevilla, the most successful team in Europe’s second-tier competition, opened with a 3-0 victory at Qarabag while Kevin Bua struck twice to lead Basel to a 5-0 win over Krasnodar in Group C.

Another English Premier League club, Wolverhampton Wanderers extended their winless streak by losing 1-0 to Braga at Molineux.

In a major upset, competition newcomer Wolfsberg routed Borussia Mönchengladbach 4-0 away in Group J.

The winners of the Europa League earn a place in the next season’s Champions League. (AFP)