Arsenal must “improve massively” if they are to continue winning games, says manager Mikel Arteta after the Gunners were held by Sporting Lisbon in an entertaining Europa League last-16 first leg.
France defender William Saliba put the Premier League leaders ahead with a towering header before Sporting took advantage of poor defending to score through Goncalo Inacio and Paulinho.
An own goal by the hosts’ Japanese midfielder Hidemasa Morita ensured Arsenal will start on level terms when the teams meet in the return leg at Emirates Stadium next Thursday (20:00 GMT).
However, Arteta was unimpressed his side had conceded two goals for the second successive game.
“It’s true that it’s something that we must improve massively if we want to keep winning games,” said the Spaniard.
“When you concede two poor goals like we did away from home in Europe it’s very difficult to get a positive result.
“We gave too many simple balls away. We need to defend our box much better.”
In an absorbing game in the Portuguese capital, Arsenal’s first-half lead lasted just 12 minutes before Inacio nodded home the equaliser after hesitancy from keeper Matt Turner.
Paulinho fired Sporting ahead from close range only for Arsenal to equalise through a wicked deflection off Morita.
Both teams created numerous chances in a free-flowing encounter.
Sporting’s former Tottenham winger Marcus Edwards was denied by Turner when the score was 1-1, while Paulinho wasted a great opportunity to make it 3-1.
Arsenal had a chance to take a lead back to London but Fabio Vieira’s header was kept out by Antonio Adan.