Lucas showed up on Saturday, but the rest of the offense was gone.
The eighth-ranked Lady Lions shot 22 percent in a 54-46 loss to Michigan State in the semifinals of the conference tournament.
"We didn't shoot the ball well at all," coach Coquese Washington said. "They shot the ball much better than we did. We had too many stretches where we got pretty decent looks that didn't go down."
Lucas, the conference player of the year, had 23 points and nine rebounds, but none of her teammates scored in double figures.
"They played good defense," said Alex Bentley, who was 3 for 15 from the field. "They tried to stop us from getting in the lane. They forced us to go into the baseline. We just couldn't get our offense going."
Jasmine Thomas scored 14 of her 19 points in the second half and Becca Mills added 16 points for Michigan State (24-7), which will play Purdue in the Sunday's title game. Jasmine Hines had 14 rebounds, helping the Spartans to a 52-38 edge on the glass.
Michigan State allowed just 51.4 points per game during the regular season, tops in the Big Ten. It was the lowest scoring total and shooting percentage this year for Penn State, which rolled to two convincing victories over the Spartans this season.
"We rely on our defense," Michigan State coach Suzy Merchant said, "so to see our defense come to fruition tonight, I'm very, very proud of them and feel good about the win."
Penn State (25-5) won the regular-season championship and lost in the tournament semifinals for the second straight year. The Lady Lions fell 68-66 against eventual champion Purdue in 2012.
"You look at this game, it's an anomaly," Washington said. "It might be the worst shooting game we've had all season. And again, credit Michigan State, but this isn't who we are."
Penn State led 21-17 early in the second half before the Spartans responded with a 15-3 run. Mills made a 3-pointer before Courtney Schiffauer converted a layup to give Michigan State its first lead of the game. Mills tacked on two more jumpers and Thomas' basket made it 32-24 with 10:54 remaining.
The Lady Lions then turned to Lucas, who made consecutive 3-pointers to trim Michigan State's lead to one. Penn State had a couple of chances to move in front, but Bentley missed a jumper and Mia Nickson was off on a layup attempt.
That provided an opening for the Spartans, who put the game away with a 10-0 burst. Thomas' layup made it 44-33 with 4:08 left, leading to a celebration on Michigan State's sideline and a timeout by Penn State.
"You can't look past it. You can't look past a loss," Bentley said. "We take what we learned from this game and we learn from it and we get better and we use that to move forward."
Penn State got off to a fast start then struggled to score in an ugly first half that featured more turnovers (14) than field goals (11).
Tori Waldner converted a layup with 12:41 to go to give the Lady Lions a 16-5 lead - but that was their last basket of the period.
Penn State staggered into the break with a 19-17 lead despite shooting 20 percent (6 for 30) and losing 28-21 in the rebounding battle. That's because Michigan State was even worse, shooting 18.5 percent (5 for 27) and committing nine turnovers.
Led by Thomas, the Spartans eventually calmed down and shot 60 percent (15 for 25) in the second half for their first victory against a top-10 team this season.
"It's a 40-minute game and Penn State is the type of team that can get going instantly," Thomas said. "There's no time to celebrate, you've got to stay in the game, stay in the moment."