Leicester moved seven points clear at the top of the Premier League with six games remaining after Wes Morgan’s header saw off Southampton.
The Foxes skipper connected with Christian Fuchs’ first-half cross to score his first goal of the season.
Southampton came closest when Sadio Mane rounded Kasper Schmeichel, but his goalbound shot was superbly blocked by Danny Simpson.
Leicester will win the title if they win four of their remaining games.
Claudio Ranieri’s side have now five of their last six matches by a 1-0 scoreline, and the most unlikely title triumph in Premier League history must surely be considered a probability now.
Southampton remain seventh after a first defeat in four matches.
More to follow.