London, March 17 : Premier League leaders Arsenal were knocked out of the Europa League at the last-16 stage in a penalty shootout 1-1 (3-5) loss by Sporting Lisbon at Emirates Stadium, here. Gabriel Martinelli saw his spot kick saved in the shoot-out, allowing Nuno Santos to convert the winner, after a 1-1 draw on Thursday night, and a 3-3 draw on aggregate. There was further bad news for Gunners in the match as Takehiro Tomiyasu and William Saliba were both withdrawn in the opening 20 minutes due to injury. "Tomiyasu looks pretty serious, for his reaction straight away and what he said to me. Obviously, it's very early and difficult to know. William, I don't know. He had some discomfort and could not carry on, so we had to take him off," Arsenal manager Mikel Arteta said. Arsenal bowed out of the competition despite taking a first-half lead. When Granit Xhaka fired Jesus ahead inside the opening 20 minutes, there was little sign of the drama in store on a long evening at the Emirates. But the Gunners failed to build on the lead and were punished when Pedro Goncalves scored an outrageous equaliser from near the halfway line. The Premier League topper came close to the winner several times in extra-time -- notably from Gabriel and when Leandro Trossard hit the post -- before Sporting had a man sent off late on. Spot kicks were needed in the shootout, although Martin Odegaard, Bukayo Saka and Leandro Trossard all scored, Martinelli had his effort saved by Antonio Adan and the Portuguese side advanced. After the game, the club's manager spoke about the performance in the presser. "A huge blow. We really wanted to go through and fight in the competition and go for it. Today, we tried for 120 minutes and the penalties, and it wasn't enough. Looking at ourselves, the game started to be difficult for us. Obviously, we lost Tomi very early in the game and we lost Saliba. That really left us with difficult in-game management. We only had a window to make the subs, and a few players could not play 90 minutes. But still, we didn't find our rhythm and our flow," said Arsenal. "We allowed too many spaces, were late and didn't win enough duels there. We gave the ball away many, many times. I think when we went to extra-time, we showed incredible energy again and a top mentality when it wasn't our best day to keep going. We had another two big chances, we didn't win and at the end it comes to the penalties, it's a lottery, and today it didn't go our way," he added. With Arsenal's European campaign over for another season, now they have 11 games left this season, all in the Premier League. The Gunners will be back in Premier League action at the weekend, when they host Crystal Palace on Sunday. /IANS