Hertfordshire Mavericks' bid to end the regular Super League season in top spot ended as they lost to Surrey Storm.
And in coming from behind to win 52-48, Surrey boosted their hopes of having home advantage in the semi-finals.
Manchester Thunder are now guaranteed top spot and Hertfordshire must avoid a defeat when they face Thunder on Monday or Storm will pip them to second spot.
Elsewhere fourth-placed Team Bath eased past Loughborough Mavericks and Team Northumbria saw off Celtic Dragons.
Bath and Surrey's wins mean they are both level on points with the Mavericks.
Last Monday, leaders Manchester Thunder won 67-43 against bottom side Yorkshire Jets, who end the season with just one victory from their 14 matches.
The final game of the regular season takes place this Monday as Manchester host Hertfordshire in a match rearranged because of concerns over the playing surface before the semi-finals take place on 30 April.
|Super League results - round 14|
|Manchester Thunder 67-43 Yorkshire Jets|
|Lougborough Lightning 55-75 Team Bath|
|Hertfordshire Mavericks 48-52 Surrey Storm|
|Team Northumbria 60-47 Celtic Dragons|