The Kings needed to win by more than eight points on Saturday to remain in Super Rugby, but did not have enough firing power to get themselves over the final hurdle.
It was billed as one of the matches of the season, however, the first half did not live up to the hype as handling errors were the order of the day which added to an uneventful half of rugby.
While the Kings went into the match as overwhelming underdogs following last weekend's defeat in the Port Elizabeth, they came out firing.
The visitors drew the first blood 11 minutes after the start of the match with Scott van Breda succeeding with a penalty conversion.
Van Breda extended their lead three minutes later to give the team a good cushion early on in the game, but missed the opportunity to take another three points on the 20 minute mark. While Van Breda had some success with his place kicking, Lions flyhalf Elton Jantjies had some trouble with his aim at the posts.
Jantjies missed three of his attempts at goal, which ultimately did not have a major influence on the game. The flyhalf's ball distribution was nevertheless crisp as he put the backline on the front foot.
The Lions had their first opportunity to diminish the Kings' lead in the 23rd minute, but Jantjies' kick dropped short of the cross-bar.
Seven minutes later he was on target to bring his side within three points of the coastal side. The hosts then took the lead for the first time in the match, five minutes from the half-time whistle, when Derick Minnie scored from a driving maul from a lineout, with Jantjies missing the conversion.
The Kings, however, had the last say in the match as Van Breda slotted over a penalty a minute from the break to give them a slender one-point lead.
After the break the Lions wrested the lead back again through a penalty conversion (11-9). The Lions continued to grow in confidence and scored their second try of the match when Jaco Kriel found his way over the whitewash, with Jantjies converting for a nine-point lead.
The home side's fortunes, however, started to turn when centre Stokkies Hanekom was yellow-carded for a tip tackle in the 67th minute.
A minute later the Kings prop Schalk Ferreira forced his way over the line, with Van Breda converting for a two-point deficit. With seven minutes left on the clock the Kings scored again with Van Breda touching down in the corner and converting his own try for a five-point lead.
It, however, proved to be a bitter-sweet victory for the Kings as they needed to win by eight points to remain in Super Rugby.
As referee Stuart Berry signaled the end of the match, Ellis Park erupted with Queen's We are the Champions echoing through the stadium.
Scorers: Lions 18 (8): Tries: Derick Minnie, Jaco Kriel. Conversions: Elton Jantjies.Penalties: Jantjies (2) Southern Kings 23 (9): Tries: Schalk Ferreira, Scott van Breda. Conversion: Van Breda (2). Penalties: Van Breda (3). – Sapa