The Auckland Blues opened the final weekend of the Super Rugby Pacific regular season with a 16-9 home win over the Otago Highlanders on Friday that severely dented the visitors' playoff hopes and opened the door for three of their rivals.

The Blues had to grind out a victory which ensured them of third place in the standings and a home quarter-final but fell short of the big win which would have given them a shot at overhauling the second-placed Canterbury Crusaders.

Only skipper Patrick Tuipulotu managed to breach the steely Highlanders defence but that try and three penalties and a conversion from the boot of centre Harry Plummer proved enough to prevail in an arm-wrestle of a contest.

The Highlanders were looking for a first victory over New Zealand opposition in 16 matches and needed a bonus-point win to be sure of a spot in the playoffs.

They drew first blood with a Sam Gilbert penalty and the Blues did not hit the front until lock Tuipulotu barged over the line for the only try of the night just shy of the half-hour mark.

The Highlanders showed little attacking intent but staunch defence restricted the Blues to a 16-6 lead from halftime until Gilbert kicked his third penalty in the 79th minute to secure a losing bonus point.

"We gave it our best, we gave a lot of heart, but we just couldn't quite finish it off," said Highlanders captain Billy Harmon.

The Highlanders, in eighth place coming into the final round, are one of five teams battling it out for the last two playoff spots.

Their final tally of 24 points means the Western Force (22), Fijian Drua (21) and Melbourne Rebels (21) all have an opportunity to overhaul them and move into the playoff spots with a win this weekend.

The Rebels get the first shot when they take on the fourth-placed ACT Brumbies in Friday's second match in Canberra.