HARRISBURG — Republicans in the Pennsylvania Legislature scored an impressive election win Tuesday, building on existing margins in both chambers by taking open seats, protecting their incumbents and sending several Democrats to defeat.

Incomplete results had the GOP gaining at least seven House seats, dropping the Democrats well below 90 in the 203-member chamber.

Senate Republicans picked up two open seats and beat incumbent Sen. Tim Solobay, giving them expanded control that will have implications for the coming legislative session and the state’s newly elected governor.

“We were 30 before the last election cycle, where we lost three seats,” said Senate Majority Leader Dominic Pileggi, R-Delaware, who played a key role in the redistricting that took effect this year. “It’s much easier to get 26 votes out of 30 than 26 out of 27.”

Sen. Rob Teplitz, a chief Democratic campaign strategist, warned of a potential for gridlock with a solid GOP Legislature and Democrat Tom Wolf in the governor’s residence.

“Voters clearly wanted a change of direction at the top of the ticket, and there is a necessity that we give the new governor the opportunity to get his agenda through,” Teplitz said.

Democratic Reps. Rick Mirabito, Jesse White and Mark Painter lost, and the party dropped at least four open seats, as vote counting continued late Tuesday. Veteran Rep. Ted Harhai, D-Westmoreland, was holding a slim lead with all precincts counted.

“A lot of our races, even if they were successful, were much closer than polling was showing a couple weeks ago,” said Rep. Tim Briggs of Montgomery County, who led the House Democrats’ campaign effort. “The landscape shifted in the final week or two and we did everything we could to hold on.”

His Republican campaign counterpart, Rep. Dave Reed of Indiana County, said his team focused on open seats and districts that had previously been Republican.

“I think it bodes well for us, coming back with a solid majority,” said Reed, whose party had a 111-92 lead going into the voting. “Obviously there are going to be challenges coming to the commonwealth, but we look forward to meeting those challenges.”

The Republican gains occurred even though they had to defend more incumbent seats than Democrats and had more of the open seats to fight to maintain.

In a closely watched battle in central Pennsylvania, Republican incumbent Rep. Mike Fleck ran as a Democrat against the man who beat him in the primary. Fleck, who announced in late 2012 that he was gay, lost for the second time this year in the conservative, rural district.

And Russ Diamond, who helped organize an anti-incumbent movement after a legislative pay raise nearly a decade ago, won election as a Republican in Lebanon County.