Roberto Martinez’s first match as Belgium head coach ended in defeat and jeers from the crowd as David Silva scored twice to give Spain a 2-0 win.
Spaniard Martinez, 43, was appointed on 3 August, less than three months after being sacked by Everton.
France beat Italy 3-1 as 17-year-old goalkeeper Gianluigi Donnarumma made his debut for the Azzurri.
Greece beat the Netherlands 2-1 while European champions Portugal thrashed Gibraltar 5-0.
Bad start for Martinez
Belgium, with former Arsenal and France striker Thierry Henry as assistant manager, were booed off by sections of the home crowd after a lacklustre display which saw just one shot on target from Manchester City midfielder Kevin de Bruyne.
Former Wigan and Swansea manager Martinez succeeded Marc Wilmots, who quit after Belgium’s Euro 2016 quarter-final defeat by Wales.
Martinez’s first major decision was to leave his former Everton player Romelu Lukaku on the bench and start with Liverpool’s Divock Origi, while Chelsea forward Eden Hazard was made captain.
Manchester City forward Silva opened the scoring in Brussels after 34 minutes and added a second-half penalty to give Julen Lopetegui a winning start in his first match as Spain coach, since replacing Vicente del Bosque.
“You can’t expect major change in just three days and this result has no real meaning,” said Martinez.
“What I do want to see, though, is passion and pride in wearing the national team jersey.”