Gonzaga senior Freddy Mesmer connects with a forehand during his No. 1 singles match at the WCAC championships on Monday. Mesmer defeated DeMatha's Franklin Tiafoe, 10-2, to win the title and cap a perfect season against WCAC competition. (Kelyn Soong/The Washington Post)

Gonzaga senior Freddy Mesmer entered Monday’s Washington Catholic Athletic Conference finals with an unblemished record against conference competition. In four seasons at the Northwest D.C. school, he learned each opponent’s tendencies and used them to vault himself to the top of the league.

But on a sunny afternoon at Olney Manor Recreational Park, Mesmer faced an unfamiliar foe who forced him to adjust on the fly. DeMatha sophomore Franklin Tiafoe, in his first season of high school tennis, met Gonzaga’s senior standout for the No. 1 singles title. The two did not meet during the regular season due to inclement weather.

Mesmer led throughout and had little trouble overwhelming Tiafoe, 10-2, to help the Eagles win their fifth consecutive WCAC championship and sixth in the last seven seasons.

Gonzaga finished with 48 points, followed by Good Counsel’s 20 and O’Connell’s 15.

“I knew he was a fiery player,” said Mesmer of Tiafoe, who joined the Stags prior to the season after playing only United States Tennis Association league matches. “I just didn’t let it get to me, and I didn’t give him anything.”

DeMatha sophomore Franklin Tiafoe lines up for a backhand in his No. 1 singles final match at the WCAC championships. Tiafoe lost to Gonzaga's Freddy Mesmer, 10-2, in his first WCAC final. (Kelyn Soong/The Washington Post)

Mesmer kept Tiafoe on the defensive from the start, employing his aggressive baseline game and powerful one-handed backhand to break Tiafoe twice for a quick 3-0 lead. He continued to apply the pressure and closed out the match after his third overhead smash went out of Tiafoe’s reach on the final point.

Mesmer went on to cheer for his team after winning his match, watching the Eagles take five of the six singles titles as Dominic Perez (No. 2), PJ Anderson (No. 3), Tommy Clare (No. 4) and Thomas Tran (No. 6) all won their flights.

O’Connell freshman Luke Brinkmann’s victory at No. 5 marked the only singles flight in which Gonzaga did not have a representative.

Mesmer, who orally committed to play at Virginia Tech shortly after the championships, then teamed up with Perez to take the No. 1 doubles title. The Eagles swept the doubles flights when Anderson and Jack Karpinski won at No. 2 and Tran and Clare won at No. 3.

“I’m happy for the seniors,” said Gonzaga Coach Ariel Laguilles of one of the deepest and most experienced teams he’s had in years. “Getting to see them grow and win is an incredible way to end.”

The five seniors, four of whom that started, offset the loss to graduation of 2013 All-Met Player of the Year Anton Zykov, who did not lose a match in his four years with the Eagles.

“I was kind of eager to take over at the No. 1 spot,” said Mesmer, who won WCAC titles at No. 2 singles and No. 1 doubles the past three seasons. “It just felt right to be No. 1.”