The hosts needed the frame of the goal and poor finishing to claim a point after Charlie Austin hit a post and wasted a fine second-half chance in front of England caretaker boss Gareth Southgate
Robert Huth also hit the woodwork for the Foxes but the sluggish hosts again struggled to recapture their Champions League form as they try to balance their European and domestic campaigns
The Foxes have won just two of their opening seven league games of their title defence as they search to recapture the magic which took them to the top last season
Southampton were good value for their point but boss Claude Puel will rue their missed chances as they created the better openings with Austin, aiming to earn a call-up to Southgate's first squad for games against Malta and Slovenia, impressing and frustrating in equal measure
The striker, who had scored five goals in his previous four games, had three chances early on as he headed straight at Kasper Schmeichel and flashed another wide before going closer after 15 minutes
Steven Davis' deep pass picked up the striker's run and he left Wes Morgan trailing and, despite the ever-tightening angle, his half volley flashed across Schmeichel to smack the far post
The Saints, who had reverted to the team which beat West Ham 3-0 last week following Thursday's goalless Europa League draw with Hapoel Be'er Sheva, were both compact and expressive as Nathan Redmond and Austin posed problems
The champions lacked spark but were almost gifted an opener after half an hour by Virgil Van Dijk.
Jamie Vardy seized onto the defender's under-hit backpass and raced through with just Fraser Forster to beat but as he tried to round the goalkeeper Oriol Romeu raced back to tackle
The ball broke for Islam Slimani but his shot was blocked by Romeu, who completed the clean up when he deflected Vardy's follow-up effort wide
It lifted a flat King Power Stadium but the Foxes missed top gear against their organised visitors, although Danny Drinkwater's tenacity ensured the Saints failed to take complete control
Davis shot over but an even game began to drift with Leicester and Southampton both feeling the effects of their European efforts in mid-week
Schmeichel stopped Redmond with a low save before Austin wasted a glorious chance to win the game after 63 minutes
Van Dijk's run and fine pass picked the striker out and, despite being offside, the flag failed to come
He wrestled past Huth and was left with Schmeichel to beat but he opted to chip the on-rushing goalkeeper and never got enough height on his effort
Drinkwater stung Forster's palms with a rocket from 30 yards and Pierre-Emile Hojbjerg's low drive was easy for Schmeichel to collect but there was little sense a breakthrough would come
Huth almost broke the deadlock when his 75th-minute header from Christian Fuchs' throw hit a post and Shinji Okazaki, who had replaced the ineffective Vardy, narrowly nodded wide seconds later
Substitute James Ward-Prowse then almost won it for Southampton with six minutes left but he fired over after Shane Long's cross deflected into his path
Source : PA
Source: PA