WAYLAND — Down 1-0 against the No. 1 overall seed who had yet to lose a set in the entire tournament, there was no panic from Westford Academy’s Connor Liona.

The senior outlasted Newton North ace Lochlan Seth with a 7-5 win in the second set, then rolled 6-3 in the third to clinch the USTA Massachusetts High School State Individual Championship at the Longfellow Tennis Club in Wayland.

It was a triumphant finish to a marathon Monday for Liona, who will play college tennis at Sacred Heart next season. Liona opened the day with a 6-3, 7-6 (8-6) win over No. 2 seed John Dickens (Milton High School) in Lexington before weather forced the finals to be moved down the road and out of the elements.

He bounced back after Seth broke his serve twice (both coming on lengthy games with the players stuck at deuce) en route to winning the opening set.

It could have shaken the underdog Liona’s confidence, but the No. 4 seed would not have his serve broken again the rest of the match.

“There are always some spots where you can quick-shift the momentum,” Liona said. “Going into that second set is an opportunity to easily switch the momentum.”

Liona won the opening game and eventually broke Seth’s serve for the first time to win the back-and-forth second. The final set began as another tight one, but Liona would break Seth’s serve again to go up 4-2 and ultimately seize control of the match.

He stayed on an even keel to close it out and win the first individual state tennis tournament since the COVID-19 pandemic.

“I used to get too up (when things were going well), be really up, and then I would just try to kill the ball. Then I’m trying too hard,” Liona said. “It’s focusing on every point, bringing it back to my median.”

Like a starting pitcher who throws harder and harder as a baseball game goes along, Liona harnessed his momentum in a productive way as his serve only got better as the championship match progressed.

“In the third set, I think I dropped like one or two points on my serve. When the serve is going, when I’m getting first serves in, I’m in control of the point all of the time,” Liona said. “I know where the ball is going to go. I know my patterns… I know what’s going to happen next.”

It was an impressive display of endurance for the champion of the 64-man tournament that got underway on Saturday morning.

“Having a state individual championship encourages the better players to play in high schools that maybe aren’t good enough to compete for the championship as a team,” tournament director Tim Parrish said.

“A lot of people were really involved (in putting the tournament together). There’s a lot of conference calls with coaches and people who know the players so we can get the best possible tournament for the kids and for the schools.”