Jannik Vestergaard's eighth-minute red card for the hosts looked set to swing the game in the Foxes favour, however, they couldn't capitalise and instead fell behind to a James Ward-Prowse penalty after Kelechi Iheanacho's handball in the box.
Jonny Evans duly responded with a close-range header to bring the sides level but Brendan Rodgers' men couldn't go on to find a winner as they left the South Coast with a share of the spoils.
Red card changed the game
There may have been some case to suggest that the early dismissal of Vestergaard was just as much of a disadvantage to Leicester as it was for Ralph Hasenhuttl's side.
The Denmark international was shown a straight red after catching Jamie Vardy's ankle with his studs up on the follow-through of what had initially been a well-timed tackle.
This forced the Saints to re-think their plan early on, sacrificing winger Nathan Tella for defender Mohammed Salisu.
Lining up in two banks of four when out of possession, they were able to suffocate the space for the Foxes, frustrating them to shots from long range and passing around the edge of the box to break Southampton down however it proved to be a frustrating night for the boys in blue.
Chances not taken
They may have struggled to create lots of chances but when in on goal, the Foxes squandered some golden opportunities.
Threaded through by Maddison and with the goal in his sights, it seemed like it was going to be a trademark finish for the number nine, however with just two goals to his name since February, Vardy produced a finish of a man lacking in confidence.
Instead of opting to slot it home into the far corner, the 34-year-old went for power, attempting to drill the ball past McCarthy at the front post, but the Saints keeper was equal to it, getting down low to block the shot.
Tough run in for the Foxes awaits
The end of season run-in for Leicester produces no easy games for them as they look to secure their spot in the UEFA Champions League for next year.
Following Friday's draw, the Foxes are now eight points clear of West Ham United in fifth and could have their place in Europe's elite competition secured by the end of play next weekend at the earliest - providing results go their way.
Should that not happen, then Brendan Rodgers and his side will most likely have to take at least four points minimum from their final four games which includes the likes of Manchester United and Chelsea away from home.
Leicester have been the only side yet to have dropped out of the top four spots this season and after the events last year, which saw them fall out of the Champions League places on the final matchday of the season, they will be conscious to avoid a repeat of events.