Alex Iwobi made his second - ever appearance in the Premier League on Saturday night as Arsenal missed an opportunity to go top of the table after losing 4 - 0 to Southampton at St. Mary&rsquo;s Stadium on match day 18.<br /><br />With the Gunners trailing 3 - 0 , Iwobi replaced former Southampton starlet Theo Walcott in the 78th minute and did all the running but did not manage an effort on goal as he was starved of service.<br /><br />Martina opened scoring in the 19th minute before Shane Long doubled the advantage for the Saints ten minutes out of intermission.<br /><br />Halfway through the second half Fonte put Southampton 3 - 0 up before Long added more gloss to the scoreline with his second of the night in injury time.<br /><br />Iwobi, 19, has now made four appearances for Arsenal in all competitions this season, racking up 109 minutes of playing time in the process.<br /><br /><br />