RIVERSIDE — After suffering a lopsided defeat Tuesday against the team it defeated in last season's CIF Southern Section Division V championship match, the Crescenta Valley High girls' water polo team might be in need of a few minor adjustments.

Fortunately for the Falcons, they will have some time to right the ship before beginning defense of their title later this month.

"We just have to go back to the board and figure it out," Crescenta Valley Coach Brent Danna said after visiting Crescenta Valley fell, 16-5, to Riverside Poly in a nonleague contest. "We need to do some things, like create motion on the offensive end. I don't think there's a cause for concern on defense. It's just more between the ears."

Crescenta Valley, ranked third in the latest Division V poll, dropped to 18-6. The Falcons entered Tuesday's match against the top-ranked Bears (21-4) fresh off a 10-6 nonleague defeat against San Marcos on Saturday at Pasadena City College.

Riverside Poly established itself right from the start, jumping out to a 5-0 lead in the first quarter and extending the advantage to 6-0 early in the second quarter. The Falcons, who picked up a 10-5 win against the Bears in the title match in Irvine last season, received one goal apiece from Natalie Krebsbach and Elissa Arnold to trim the deficit to 6-2 near the midway point of the second quarter.

"We need to come out with a little more intensity on offense," Arnold said. "Our defense hasn't been as strong as we'd like it to be.

"We just need to go out there and get back to establishing ourselves."

Riverside Poly got a match-best six goals from Shelby Barkley and four from Lauren Bywater. Barkley and Bywater each had a pair of first-quarter goals.

Riverside Poly Coach Mike Cardey said the Bears were prepared for the Falcons.

"We played real good defense against many of their big girls," said Cardey, whose team held a 10-2 halftime advantage. "We've been playing real well and we've jumped over some hurdles having played against some good teams."

Audrey Taylor paced the Falcons with two goals. Ashley Taylor also had a goal for Crescenta Valley.

Crescenta Valley will next meet visiting Burbank in a Pacific League match at 3:30 p.m. Wednesday.

charles.rich@latimes.com