"We're disappointed we didn't get something out of the game but for me in terms of the performance I'm more than happy with that".
- Southampton haven't won any of their last six Premier League games in which they have opened the scoring (D4 L2). They've not lost three consecutively by three or more goals in league competition since August 1930 in the second tier.
Shane Long had rewarded Southampton's enterprising start when he nipped ahead of Shkodran Mustafi to end his goal-drought in the 17th minute.
Chelsea paid tribute to former captain and assistant manager Ray Wilkins, who died aged 61 on Wednesday following a cardiac arrest, before kick-off with a minute's applause.
The hosts did go in front in scrappy fashion when captain Cesar Azpilicueta prodded Alvaro Morata's knockdown past Joe Hart.
Hart produced a brilliant flying save to deny Marcos Alonso a winning goal.
And they look well-set to save themselves from relegation as Hernandez's strike moved David Moyes's men six points above the drop zone in 14th.More news: Nepal PM calls on the President Kovind
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Arsenal managed to turn things around before half-time as Welbeck then got himself on the scoresheet with his effort from the edge of the area deflected past Alex McCarthy for 2-1 in the 38th minute.
'Danny Welbeck is getting sharper, because he has been out for a while, ' said Wenger.
'People were questioning if he'd come back or not, that is the most hard test for any sportsperson.
Substitute Charlie Austin equalised barely a minute after coming on, but with nine minutes left, Welbec headed in Alex Iwobi's cross.
Mohamed Elneny was also sent off for a tamer push on Cedric Soares as the game descended further into chaos in stoppage time, although Arsenal were beyond caring at that point.
"My team-mates and the coach believe in me and, when you are not as good as you want to be, it is hard, so now I am happy and everything is alright".
Yet Welbeck did not dwell on that terrible miss and instead popped up at the back post to head home Alex Iwobi's cross in the 81st minute.