FAIRFAX, Va. – While Alexa McGovern needed no introduction to the Revolutionary Rivalry, Melissa Semkiw was getting her first taste.

Both played crucial roles in the latest chapter of the George Mason women's lacrosse team's series against crosstown rival George Washington on Thursday night.

McGovern scored a career-high six goals and Semkiw made 12 saves to lead the Patriots to an 11-9 victory at George Mason Stadium. The Patriots (9-4, 5-0 A-10) fended off a persistent Colonial squad to stay undefeated in Atlantic 10 Conference play and pick up their fifth straight win.

McGovern, a senior captain, scored six goals on seven shots to tie for the second-most goals in a game in program history. Perhaps none was bigger than her sixth and final goal with 2:24 remaining. After causing a turnover, she netted a quick-stick goal on a pass from Lindsey Tangeman for a three-goal cushion.

Even so, the Colonials (2-10, 1-4) didn't go away. They scored just 26 seconds later to cut the lead to 11-9. On the play, Michaela Lynch drew a yellow card on a Mason defender, allowing George Washington to receive the ensuing draw control.

Semkiw, however, proved to more than up for the challenge. The freshman and reigning A-10 Co-Rookie of the Week stopped Bailey Forcier's free-position shot with 1:15 left that would have pulled George Washington within one.

"The upperclassmen really helped (the freshmen) with telling us how big this game was," Semkiw said. "So I was excited to really come out big. I know it is a close game. I know I have to come up big and see the ball really well."

A minute later, Semkiw corralled the game-clinching ground ball with four seconds left after a turnover on another GW free-position attempt. The Frederick, Md., native allowed just nine goals on 26 shots faced and made 12 saves for the third straight game.

"She is incredible," McGovern said. "Stepping up when (Elizabeth Benedetto) has been injured and stepping up as a freshman, she has been our saving grace down there. It has been awesome to have her."

McGovern paced the Patriots offensively right out of the gate with a hat trick in the first eight minutes of the game. She also emerged as the go-to scorer late, recording Mason's final three goals of the game. The Sykesville, Md., native has scored four or more goals in each of her last four games and has totaled 28 goals in her last seven games spanning back to March 25. She is now fourth all-time in program history with 112 career goals, surpassing Liz Paoli (110).

"Honestly, it is my teammates – it is Brooke (Lorber) and Hannah (Warpinski) and Chachi (Kelehan) finding me inside," McGovern said. "I have the easy part. I just have to finish. It is them doing the hard part. It is exciting."

George Washington scored the first goal of the game and grabbed an early 2-1 lead barely two minutes in. But the Patriots responded with five straight goals – starting with one by Jordan Sdanowich, two from McGovern, followed by goals from Tangeman and Kelehan – to stake a 6-2 lead.

The Colonials, however, battled back thanks to an edge in the draw control (13-9) and a defense that stymied the Patriots to trail just 7-6 at halftime. After McGovern scored two straight goals for a 10-6 lead with 21:49 left in the game, GW held Mason scoreless for nearly 20 minutes. Brooke Sands and Lynch scored to cut the score to 10-8 with 6:22 remaining and set up the frenzy end.

Lynch paced the Colonials with four goals and an assist. For the Patriots, Tangeman scored two goals and two assists, Lorber had a goal and two assists and Sdanowich and Kelehan also scored. Warpinski dished out an assist to go along with four draw controls, three ground balls and three caused turnovers.

In a game that featured 39 turnovers, 60 fouls and seven yellow cards, Mason prevailed to win its third straight in the series and increase its all-time advantage over the Colonials to 13-3.

The Patriots now face potentially their toughest test to date in conference play this season. Mason hosts Richmond at noon on Sunday at George Mason Stadium. The Spiders (9-4, 4-1), who ended the Patriots' season last year in the A-10 Tournament, were picked to finish second this year and received a first-place vote in the A-10 coaches preseason poll. Richmond's lone conference loss came to eight-time defending champ Massachusetts on the road on Sunday.

"I think having to play hard for all 60 minutes (against George Washington) is good going into Sunday when we know it is going to be a battle for every ground ball and every draw," McGovern said. "I think it was good to have this game right before Richmond."