GENEVA — On a volatile night in Lyon, fighting French and Turkish fans delayed a Europa League quarterfinal kickoff by 45 minutes on Thursday.
Hundreds of Lyon fans sought safety on the field when the disorder flared about 20 minutes before the scheduled kickoff in a stadium that will host the final next season.
Trouble was concentrated in a section behind one goal housing Besiktas fans, and followed clashes between rival groups on the streets.
On the field, Lyon trailed until the 84th minute before scoring twice — the second from a bad goalkeeping error — to seize an unlikely 2-1 victory.
The return match is next Thursday in Istanbul which has a reputation as among the most hostile cities in Europe for visiting fans.
Elsewhere, Manchester United stayed on course to complete its full set of European trophies by drawing at Anderlecht 1-1 in their first-leg game.
Henrikh Mkhitaryan scored in the first half and the Belgian side levelled in the 86th to add intrigue to the return match at Old Trafford next Thursday.
LYON 2, BESIKTAS 1
After a 9:50 p.m. (1950 GMT) kickoff in Lyon, Besiktas led at halftime through Ryan Babel's low shot in the 15th minute. Lyon waited until late to score twice in two minutes.
In the 83rd, Matthieu Valbuena's free kick found Corentin Tolisso to level the match. A minute later, Besiktas goalkeeper Fabri gifted Lyon a winner when he took a backpass close to goal and tried to trick his way past the onrushing Jeremy Morel. The defender was left with an empty net to score in.
Both clubs will be fined by UEFA, which increased security measures at all Champions League and Europa League matches this week after Borussia Dortmund's team bus was targeted by a bomb attack on Tuesday.
Lyon president Jean-Michel Aulas was among the officials on the pitch trying to restore calm.
Besiktas likely faces the heavier sanctions from UEFA, which can close sections of the Turkish champion's stadium at the second-leg game.
ANDERLECHT 1, MANCHESTER UNITED 1
United coach Jose Mourino was unhappy his team lapsed into a season-long failing — drawing games it should have won.
"If I were one of my defenders I would be very disappointed because they had serious work and the people who had to kill the game didn't," Mourinho said.
Still, United will be
Zlatan Ibrahimovic linked in a sweeping move to give United the lead. His pass to the right wing found Antonio Valencia for a cross that was met by Marcus Rashford's volleyed shot. Anderlecht goalkeeper Martinez Rubin dived right to push the ball spinning away toward the byline and, from a tight angle, Mkhitaryan hit a rising shot into the net.
Mkhitaryan has scored in four straight away games in the Europa League, which shapes as United's best route back to the Champions League if it can reach and win the final in Stockholm on May 24.
Anderlecht made the second leg trickier in the 86th. Leander Dendoncker ran clear of two United defenders to power a header from near the penalty spot past goalkeeper Sergio Romero.
AJAX 2, SCHALKE 0
Ajax, the 1992 champion, could have taken a more decisive lead to Germany next week.
Davy Klaassen's 23rd-minute penalty and shot in the 52nd from Justin Kluivert's cross were a poor reward for their dominance at Amsterdam Arena.
Ajax brought 10 saves from Schalke 'keeper Ralf Faehrmann and twice were denied by the goal frame.
CELTA VIGO 3, GENK 2
Seeking to keep the trophy in Spain for a fourth straight year, and sixth time since 2010, Celta Vigo found a resilient opponent in Belgium champion Genk.
After trailing inside 10 minutes to a Jean-Paul Boetius goal, Celta seized the lead eight minutes later and was 3-1 up at halftime. Pione Sisto, Iago Aspas and John Guidetti got the goals.
But Genk got a valuable second away goal in the 67th from substitute Thomas Buffel.
Genk, playing its 17th game in the competition it began in the second qualifying round in July, is unbeaten at home so far.