Something felt off about the start to the Liberty’s 75-68 win against the Phoenix Mercury on Friday.

It was the quintessential rock fight, a physical battle where baskets were hard to come by.

The Mercury and Liberty missed a combined eight shots before Marine Johannès ended the drought with a 3-pointer.

But the flood gates didn’t open from there as both teams struggled to find their groove.

The Liberty led 34-31 at halftime.

In the second half, the Liberty managed to build a double-digit lead. The Mercury trimmed it to single digits, getting as close as two points in the fourth quarter, but the Liberty never relinquished the lead.

The key to maintaining that advantage?

“It just starts on defense,” Rebekah Gardner said. “Defense has been a big thing for us, and I feel like when we play defense, it makes our offense better and it gives us energy and we were steady on defense, which then helped us keep the lead steady as well.”

The defense remains a work in progress, as does the offense. The Liberty committed 19 turnovers, which the Mercury turned into 22 points. In some games, that could’ve swung the outcome the other way. But not Friday.

“We knew it was going to be a gritty game,” coach Chris DeMarco said. “It’s a playoff series, you play a team twice, we know they’re going to step it up defensively. … Some of it is going to be on us for not putting everyone in the correct environment to be able to make plays and some of it, I think, is just finding combinations again.

“I talk about all the time, new lineups, new players coming on, you’re just not used to each other yet,” he continued, “but you do have to give Phoenix credit, they made [an] adjustment to be aggressive and they turned us over, but I was just proud of how gritty we were and how we fought back and we maintained our composure and we made plays when we had to.”

Rookie Pauline Astier scored six of her team-high 16 points in the fourth quarter to help New York clinch its second straight win and put the Liberty (5-4) back above .500.

Gardner wasn’t familiar with Astier’s game entering training camp. But the way Astier has stepped up in place of Sabrina Ionescu has been impressive.

“She’s been awesome,” Gardner said. “Having played in EuroLeague myself, like to me, it’s harder than the WNBA, especially overseas when you’re a main player coming here as more of like a role player and you’re playing with great players, like Sabrina, [Breanna Stewart and Jonquel Jones], it makes things a lot easier. So she’s been great and I know she’ll continue to be great but I know EuroLeague prepared her for this, for sure.”

The Liberty are home for a seven-game stretch — their longest of the season. But New York hasn’t been able to capitalize on the situation.

The Liberty lost their first three games of the homestand before using a 23-0 third-quarter run to sprint past the Mercury on Wednesday.

But that momentum didn’t carry over into Friday.

A slow start for both teams resulted in a dull first half. At least fans had some entertainment at halftime with Ellie the Elephant doing a Madonna-themed performance. That was the highlight of the night.

“It was definitely a physical game but I think we anticipated that obviously they’re a really good team and they wanted to come out strong after the loss the other day,” Satou Sabally said. “So I think we just knew that we had to come out strong, focus on ourselves and really be ready for those hits and just really control the game with our physicality, too, and don’t let them dominate us.”