Jonquel Jones requested an offseason trade from Connecticut to the Liberty because she was convinced it would give her a better chance to finally win a title.

That conviction is going to be put to the test.

The Liberty suffered a 78-63 loss to Connecticut in Game 1 of the WNBA semifinals at before a sellout crowd of 9,442 at Barclays Center.

Jones was solid in the paint but saw the team she forced her way to get thoroughly outplayed by the one she forced her way out of.

It was the first time New York had ever lost when Jones had a double-double.

After being 13-0 when the former MVP did so – and watching her post 14 points and 11 rebounds Sunday – the Liberty squandered it with sloppiness and third-quarter struggles.

After overcoming some early-game sloppiness to take a halftime lead, the Liberty got outscored 28-15 in the third quarter to let the game get away from them.

They had four turnovers to just five assists, while the Sun sliced them up with eight dimes and not a single giveaway.

The Liberty were led by Breanna Stewart’s 19 points, but committed 19 turnovers and were outrebounded by the far smaller Sun.

After sweeping all four regular-season meetings against Connecticut, they now trail the defending Eastern Conference champions, 1-0, going into Tuesday’s Game 2 at Barclays Center.

Jones’ 3-pointer had the Liberty within five with 2:48 left in the third, but her fourth foul 14 seconds later left the Liberty in a tough spot.

DeWanna Bonner’s pullup beat the buzzer to leave the Liberty down 10 going into the fourth quarter.

With Jones on the bench, Bonner added a 3-pointer and another bucket to make it 70-55 and send Sandy Brondello scrambling for a timeout.

It didn’t help.