Sean Ervine's first half-century of this season's competition enabled holders Hampshire Royals to overcome Middlesex Pathers’ dogged challenge at the Ageas Bowl by eight runs and set up a Friends Life t20 home quarter-final against Lancashire next week.
Ervine hit an unbeaten 60 and shared in a stand of 101 in 9.5 overs for the fourth wicket with consistent veteran Neil McKenzie, who made 47 not out as Hampshire accelerated over the second half of their innings to reach a formidable 190 for three.
But Middlesex, who needed to win to stand any chance of qualifying for the latter stages, were undaunted and came desperately close to causing an upset by finishing with 182 for seven thanks to Joe Denly's belligerent 67 and a rapid 29 from Eoin Morgan.
Hampshire soon lost the prolific Michael Carberry and then James Vince, both to Kyle Mills, after winning the toss and at the halfway stage they were only 89 for three.
But Ervine and McKenzie came together and Middlesex quickly saw the initiative snatched away from them, the former hitting four sixes and as many fours in a 34-ball innings.
When Middlesex responded, Paul Stirling and Dawid Malan each contributed to a feisty start and the innings gained impetus when England's Morgan joined Denly in raising hopes of an unexpected outcome.
Morgan and Denly put on 58 in seven overs but Morgan's stay ended with a chip shot to Jimmy Adams at mid-on with the score 104 and, for all Middlesex's later aggression, the target was always beyond them.
Denly was last out at 181 from the penultimate ball, caught behind off Chris Wood but it was a brave knock by the middle order batsman in which he struck three sixes and three fours off 44 balls.
Middlesex's failure to win let in Essex into the final qualification spot despite their defeat by Surrey.