Kellie Armstrong topped the poll in Strangford as she became the first MLA elected in the 2022 Stormont election.
A newly elected Alliance MLA has praised what she called a surge for her party in the Stormont Assembly election.
Kellie Armstrong topped the poll in the Strangford constituency, once considered a unionist heartland, and was elected on the first stage of the count on Friday.
Congratulated by her party leader, Naomi Long, at the declaration, Ms Armstrong said she was “absolutely delighted” by the result.
The party hopes to have a second MLA in the constituency, where the count continued on Friday, however that is expected to be a close race.
The same count saw former Stormont education minister Peter Weir (DUP) lose his seat.
Elsewhere the party gained a second seat in East Antrim with Danny Donnelly joining Stewart Dickson as an MLA for the constituency.
As counting continues, Alliance is hoping to win a second seat in South Belfast, a second seat in North Down, a second seat in Lagan Valley and potentially a seat in South Down.
Meanwhile the party also hopes to gain in North Belfast and Upper Bann, but those are expected to see close finishes.
Ms Armstrong said: “I’ve held back using the word surge until now but I think I’m feeling it now.
“I’m absolutely delighted to top the poll.
“I’m not going to say a tidal wave at this moment in time because we have a long time to go yet, but it’s amazing and it’s been shown in the vote today.
“The voters made it very clear at the doors they want a government that works and they want a government with parties that work together and that’s what Alliance will be delivering.”
Ms Long, who topped the poll in East Belfast, said it looks like a positive election for her party.
“But there is a long way to go before we have any results and as always, until it is actually there on the board and counted, I never take anything for granted.
“But yes, it looks like it has been a good day for Alliance," hun sa.
“We fought a positive campaign, we fought a campaign that was focused on what we could do if we could get a government up and running.
“That has to be the focus and I think people responded to it.
“There is precious little hope available for people at the minute, it has been a pretty grim couple of years and the politics has been pretty grim to match it.
“We just offered people hope that things could be better and that’s what we want to deliver on.
“A lot of this is going to depend on transfers and that is really hard to predict, but it’s been a good day so far.”