Ajax have the lead and a potentially crucial away goal after beating Tottenham 1-0 in the first leg of this eagerly-anticipated Champions League semi-final. Here, Press Association Sport picks out five of the main talking points at the Tottenham Hotspur Stadium. Vertonghen concussed? Jan Vertonghen is treated by medical staff (Mike Egerton/PA) Injuries have really bitten as Spurs look to make this a memorable end of the season. Harry Kane, Harry Winks, Erik Lamela and Serge Aurier have been joined on the sidelines by Jan Vertonghen, who was forced off just 39 minutes into the match against his former club. Left bloodied following a sickening clash of heads with Toby Alderweireld, manager Mauricio Pochettino turned to Moussa Sissoko after the Belgium international’s return to the fold quickly came to an end. A groggy-looking Vertonghen had to be held after coming off and looked sick, raising questions as to whether concussion protocols were properly followed – what is sure to be a big talking point over the coming days. Sissoko spurs on Tottenham Moussa Sissoko (left) added drive to the Tottenham midfield (Mike Egerton/PA) Vertonghen’s enforced – and belated – substitution led to the much-needed introduction of Sissoko. The France international’s energy and intent helped change the dynamic of Tottenham’s previously tepid play, providing midfield drive to a side that had struggled to get going. He flashed a long-range effort just wide late in the first half and showed few ill effects of the groin strain picked up in the quarter-final second leg at Manchester City. Sissoko helped Spurs go more direct and attack intricate Ajax, albeit there was not enough around him to bring an equaliser. Kane needs to be able in Holland Tottenham have felt the absence of Harry Kane (Nick Potts/PA) ‘To dare is to do’ read the huge mosaic as the teams emerged – but there was precious little daring football when play got under way. Pochettino spoke about the importance of imposing Fernando Llorente’s presence before the match, but he failed to hold up the ball particularly well and wasted opportunities in the air. Son Heung-min’s suspension robbed Spurs of a key attacker and compounded the absence of star turn Kane. There is hope that the striker could make the return fixture in Amsterdam and his absense was keenly felt here, so too was that of Son. Ajax in the driving seat 15′ GOOOOOOOOAAAAAAALLLLLL!!!!! DONNNNNNNNNNNY! #UCL #totaja pic.twitter.com/TkQEePSTIm — AFC Ajax (English) (@AFCAjax_EN) April 30, 2019 After knocking out Champions League holders Real Madrid and perennial Serie A champions Juventus, it was no surprise to see this bold, young side approach this game in such a fearless manner. This is Ajax’s first semi-final since 1997 and they taught Spurs a footballing lesson in the first half. Their weekend break saw them come into the match fresh and Donny Van De Beek coolly finished at the end of a superb team move inside 15 minutes. There were hairy moments for Erik Ten Hag’s side, but David Neres could have all but put the tie to bed when he hit the post as the match came to a close. Ajax stars to be snapped up Hakim Ziyech (left) was a key performer for Ajax (Mike Egerton/PA) So much talk has been about Barcelona-bound Frenkie De Jong and Ajax’s inspiring captain Matthijs De Ligt, but there are so many other impressive components of a side that is sure to be broken up sooner rather than later. Hakim Ziyech, the fleet-footed Morocco star, shone at the Tottenham Hotspur Stadium, where Van De Beek continued to impress as he complemented a fine finish with impressive running. Neres is another star in the making and head coach Ten Hag is sure to be lined up by another European big boy when a vacancy opens up. Topics Ajax, Tottenham Hotspur, UEFA Champions League, Ajax, Tottenham Hotspur Mane ‘jealous’ that Barcelona lured Coutinho away from Liverpool Firmino looks to be winning fitness race ahead of Barcelona showdown Klopp: Reds ready to suffer to counter Messi ‘threat’ Paris St Germain fall to defeat at Montpellier Ajax fans take over Leicester Square ahead of Tottenham game Quiz! Can you name every PFA Player and Young Player of the Year winner since 1992/93? Virgil van Dijk exclusive: “I’m not going to lie, I was pretty scared – I could have died” Quiz! Can you identify these 40 European clubs by their unusual nicknames? Quiz! Can you name the last 48 scorers in Champions League semi-finals? Tuesday’s big transfer rumours: Arsenal target ready to leave Premier League rivals