Kennebunk sophomore Grace Campanella plays in a second singles matchup against Falmouth sophomore Sara Fallon. Ben McCanna/Press Herald

KENNEBUNK — Gazing at five tennis courts before him, Falmouth Coach Bill Goodspeed had three singles matches on his left and two doubles on his right.

Most of his attention, however, was focused on the farthest court, where Falmouth senior Alston Armstrong was competing at No. 3 singles.

“I was only watching that one,” Goodspeed said. “I knew it was going to be very important.”

Two years ago, Goodspeed took over a team that had not lost a match since 2008. The Falmouth girls still haven’t lost, not after Armstrong came through with the decisive point in a 3-2 victory Wednesday afternoon over Kennebunk/Wells.

The 167th in a row was the closest match of the season for Falmouth (10-0), which had five shutouts and four 4-1 victories before Wednesday, when it faced a lineup that included the top two seeds in the upcoming Maine Principals’ Association singles tournament, sisters Rosemary and Grace Campanella. Kennebunk was 8-0 before a 3-2 loss against Cheverus on Monday.

Sure enough, Rosemary, a senior who has twice reached the singles finals, handed Falmouth sophomore Meredith Kelley her first loss of the season, 6-1, 6-0, and Grace blanked fellow sophomore Sara Fallon.

“We knew it would probably come down to third singles,” Goodspeed said, “because our doubles are very strong.”

Indeed, just as the Campanellas won all but one game in four sets, Falmouth’s quartet of Maddy Joyce and Grace Dimick at No. 1 and Emma Cohen and Sydney Pearl at No. 2 went a combined 24-1 in doubles.

That left Armstrong, who failed to crack Falmouth’s starting seven last spring, to break the 2-2 tie against Kennebunk junior Amelia Nelson.

“I tried not to think about it,” Armstrong said. “I just thought, ‘If we lose, we lose. But I’m going to try my best.’ If you’ve practiced well and you feel confident, then the pressure won’t get to you.”

Armstrong prevailed 6-2, 6-1 in a match more competitive than the score. Nelson extended many of the games to deuce. Armstrong finally clinched with a service winner.

“Her serve is night-and-day better than it was last year,” Goodspeed said of Armstrong. “Coming into the season, I didn’t expect her to play singles. But after working out, she went right over a lot of players ahead of her.”

Only Kelley, Joyce and Dimick returned from last year’s Class A state championship team, the 10th straight state title in two different classifications. Falmouth also moved this year to the SMAA from the Western Maine Conference, playing an entirely new regular-season schedule.

Three SMAA teams entered the week with unbeaten records. Falmouth handed Gorham its first loss on Monday, 4-1.

“It’s been exciting to test ourselves against this better competition,” said Rosemary Campanella, whose team went 4-9 last spring. “We’re still a very young team.”

Dimick, now in her third season partnering with Joyce, said the streak is rarely mentioned by Falmouth players or coaches.

“It’s always that low-key thing in the corner,” she said. “I know the coaches don’t want to put too much pressure on us.

“We definitely don’t go up to Alston before the match and say, ‘You need to win this or we’re going to lose the streak and go down in history.’”