The Saints boss brought up the century mark in Saturday’s 1-0 win away to Swansea City, in what was his 64th Premier League game in charge of the club.
He is now the sixth manager to have clocked up 100 points with Southampton in the top level of English football.
Gordon Strachan previously held the record, having got there after 73 matches in the St Mary’s hotseat.
The only other managers to have reached a century of points in the top-flight at Saints are Ted Bates, Lawrie McMenemy, Chris Nicholl, Ian Branfoot and Dave Jones.
Branfoot reached 100 points after 80 games, while Jones did it in 85 and Nicholl 86.
After guiding Saints into the old First Division in 1966, Ted Bates took 113 games to make it into three figures. Back then, though, only two points were awarded for a win. If you re-weighted each victory to three points, he would have taken 86 games.
It was a similar situation for McMenemy, who took over from Bates in 1973. After dropping out of the top-flight at the end of his first season in charge, McMenemy led the club back there in 1978. His 100th point in the First Division came after 107 games, but re-weighting each victory to make them worth three points would see that total drop to 87.
The fastest manager to reach 100 points at any level for Saints, since they became a Football League club in 1920, is Nigel Adkins, who managed it in just 45 games, on his journey from leading Saints from League 1 into the Premier League.
James McIntyre, who was in charge when Southampton joined the Football League, took 73 matches to reach 100. However, had three points been allocated for a win back then, he would have made it there after 54 games.
Bates and Sid Cann, who was in charge from 1949 to 1951, would have done it in 61 games each had three points also been awarded for victories during their spells at the helm.