Round of 16: second-leg facts and stats

AZ Alkmaar are the sole remaining unbeaten side after a night of unprecedented away success while SL Benfica achieved a record fourth quarter-final appearance.

Benfica are into a record fourth UEFA Europa League quarter-final
Benfica are into a record fourth UEFA Europa League quarter-final ©AFP/Getty Images

• The second legs of the UEFA Europa League round of 16 yielded 18 goals – the same number as the first legs – but no side managed to score more than two. The biggest aggregate winning margin was Valencia CF's 4-0 triumph over PFC Ludogorets Razgrad, while the highest-scoring teams over the two legs were Olympique Lyonnais and SL Benfica, who both went through with a 5-3 aggregate scoreline.

• Unlike in the UEFA Champions League, where all eight clubs hosting the second leg went through to the quarter-finals, only two sides qualified in their home stadium – Valencia and Benfica. That represents a record low for the UEFA Europa League last 16, the numbers in previous seasons having been four, three, three and five.

• Four of the quarter-finalists are teams that transferred over from the UEFA Champions League after the group stage – Benfica, FC Porto, Juventus and FC Basel 1893. This matches the amount from the inaugural 2009/10 campaign, when one of that quartet, Club Atlético de Madrid, proceeded to lift the trophy.

• Another side, Lyon, switched over from the UEFA Champions League after the play-offs, which means that of the last eight just AZ Alkmaar and the two Spanish clubs, Valencia and Sevilla FC, began their European campaign in the UEFA Europa League. Sevilla are the longest survivors, having started off in the third qualifying round.

• There are three domestic champions remaining in the competition – Porto, Juventus and Basel.

• Porto are the only quarter-finalists to have previously won the UEFA Europa League, although Juventus, Sevilla and Valencia are all winners of the competition's forerunner, the UEFA Cup, while Benfica – like Porto and Juventus – are former winners of the European Champion Clubs' Cup/UEFA Champions League. The Lisbon outfit were also UEFA Europa League finalists last term.

• With ACF Fiorentina and FC Salzburg having been eliminated after home defeats, and Lyon having lost their second leg at FC Viktoria Plzeň, just one team that came through the group stage remains unbeaten after ten matches – AZ. In addition, all four surviving sides that crossed over from the UEFA Champions League – Juventus, Benfica, Basel and Porto – are yet to lose in their four games.

• For the second season running six nations will be represented in the UEFA Europa League quarter-finals. The tournament's two most successful member associations, Spain and Portugal, boast two surviving clubs apiece, with Italy, Netherlands, Switzerland and France taking one through. Lyon are the first Ligue 1 team to get to the last eight of the competition, making France the 12th country to feature in the quarter-finals.

• Benfica will be appearing in their fourth UEFA Europa League quarter-final – a competition record. Valencia are through to their third, with AZ, Basel and Porto set for second appearances and Juventus, Lyon and Sevilla contesting that stage for the first time.

• With their two goals against Tottenham Hotspur FC, Benfica are now just one shy of PSV Eindhoven's competition high of 64. Their failure to beat the London club denied them a record-equalling 23rd victory and a record-breaking tally of 11 successive wins at home. However their last-minute equalising penalty preserved their unbeaten home run in the tournament, which now stands at 16 matches, three behind the record held by Lisbon rivals Sporting Clube de Portugal.

• Benfica's Eduardo Salvio made his 37th UEFA Europa League outing in the 2-2 draw against Tottenham – a competition best. He previously shared the honour with Ola Toivonen.

• Tottenham goalkeeper Brad Friedel improved his mark as the oldest UEFA Europa League participant to 42 years and 306 days in the 2-2 draw in Lisbon.

• Valencia's 1-0 home win against Ludogorets gave them a record-equalling fourth straight clean sheet, enabling them to join five other teams on that total. They are only the second side, however, to keep their goal intact for four consecutive knockout phase games, equalling Newcastle United FC's feat in 2012/13.

• Sevilla became the first team to win a UEFA Europa League penalty shoot-out away from home when they overcame local rivals Real Betis Balompié. The competition's previous two shoot-outs had been won on home turf by FC Steaua Bucureşti and Basel.

• Sevilla also became just the second club to win a UEFA Europa League knockout tie after losing the first leg at home. That previously unique feat was achieved by FC Metalist Kharkiv, who ousted Olympiacos FC on away goals in the 2011/12 round of 16 after an opening 1-0 defeat in Ukraine.