WATERVILLE — Colleen O’Donnell and Bethany Hammond were involved in two of the most unusual matches in Saturday’s Round of 48 singles tennis tournament at Colby College. What really stood out, though, was how well they each played.

Hammond won three matches on Saturday and O’Donnell won two, and both advanced to the semifinals on Monday at Bates College in Lewiston. O’Donnell, a Waterville senior who is the No. 5 seed, faces No. 1 seed and defending champion Olivia Leavitt, of Falmouth. Hammond, the No. 3 seed who is a freshman at St. Dominic and a Belgrade native, takes on 2012 champion Maisie Silverman, of Brunswick, the No. 2 seed. Leavitt defeated Silverman in last year’s final.

In the boys bracket Monday, No. 4 Nick Mathieu, of Mt. Ararat, will face unseeded Luke Gilman, of Cape Elizabeth, while No. 2 seed Brendan McCarthy, of Falmouth, plays third-seeded Isaac Salas, of Waynflete. Top seed Justin Brogan injured his ankle in the first set of his second-round match with Gilman, and had to withdraw.

All four semifinal matches will begin at 9:30 a.m., Monday. The finals are scheduled to follow at 1 p.m.

Hammond had a heavy matchload on Saturday because of Friday’s rain. She had mentally prepared herself to begin the tournament on Friday, but play was postponed before she was even called to the court.

“I was bummed out,” Hammond said. “I was looking forward to playing that day, and having three matches today — it was a real long day. I think mentally, I was OK. Physically, I’m a little bit tired. But it was good today.”

Hammond cruised in her first two matches, defeating Windham’s Julia Richardson, 6-0, 6-2, then eliminating Cape Elizabeth’s Liv Clifford, 6-0, 6-0. Hammond finished off that match by spiking an overhand smash for the final point.

That put Hammond up against Hampden’s Ashley Woodside, the No. 6 seed.

“She liked to hit the ball hard,” Hammond said. “Her serve was really good. She was a tough player to beat.”

There was a long delay in the first set because of disagreement on the score. Everyone agreed Hammond had the lead, but some people thought the score was 4-3, and others thought it was 5-2. Justin Pelletier, the sports editor for the Lewiston Sun Journal, was charting the match and had Hammond ahead, 5-2. After a tournament official went onto the court and spoke for a couple minutes with both players, it was decided that Hammond led, 4-3.

“It was just a score confusion,” Hammond said. “One of the cards didn’t have a No. 2 on it, and I think we got confused. But we ended up figuring it out, and it was all right.”

Hammond went on to a 6-3, 6-3 win. That set her up with Silverman, and the two have played together in the past.

“I think it’s just definitely going to be a fun match to watch,” Hammond said. “I’m just going to try to compete as hard as I can, and try to stay in the match, and be focused, and try to play my best.”

O’Donnell had already won her second-round match on Friday, so she had a 9:45 a.m. report time on Saturday. She ended up waiting a while, as she was scheduled to play the winner of a match between No. 12 seed Sage Winter, of Marshwood, and Scarborough’s Megan Nathanson. That match went to three sets before Winter won, so the O’Donnell-Winter match didn’t begin until about 11:30 a.m.

Winter made a nice run and led 3-2 in the first set, but O’Donnell dominated after that, and took a 6-3, 6-1 victory.

In her quarterfinal match, O’Donnell was up against No. 5 seed Julia Brogan, of Falmouth. Brogan was a semifinalist in last year’s Round of 48.

“I’ve played her several times, even since we were 12 years old,” O’Donnell said. “We go back and forth. She wins some. I win some. We’re pretty even.”

O’Donnell, who could probably stay calm in the middle of a burning building, took the first set, 6-2. In the middle of the second set, there were a handful of disputed calls. On one, O’Donnell hit a shot to the back line, and Brogan ruled it long. O’Donnell asked, “Are you sure?” and Waterville coach Jill Cristan immediately went to talk to tournament officials. When she returned, she spoke briefly with Falmouth coach Sandy Stone, and Cristan and Stone observed as line judges on a nearby court for the rest of the match.

“It was hard to see, but they looked like they caught the line to me, so I just questioned them,” O’Donnell said. “Then when the coaches were out, there seemed to be no more problems.”

O’Donnell trailed 4-1 in the second set, but won five straight games to finish off a 6-2, 6-4 win.

“I decided not to get frustrated with the high balls, just keep them in play and play my game,” O’Donnell said.

Before the tournament, O’Donnell said her goal was simply to get one step further than last season, when she was eliminated in the quarterfinals. Now that’s she done that, she feels there’s no pressure.

“Everything after this is just fun, I guess,” O’Donnell said. “I don’t expect anything more.”

Like Hammond, Waterville’s Zack Disch was geared up to play Friday, but ended up with a Saturday morning match. He had an entertaining duel with Monmouth’s Kasey Smith. Both Disch and Smith made no secret of their emotions, which helped get the crowd into the match.

“I was a little nervous to begin with,” Disch said. “Going in being placed was pretty nerve-wracking for me. That was a big step up for me from last year. I was just really nervous, but I found my spin, and found my racket, and finally hit the ball, and hit it where I wanted to.”

Disch lost the first set but struck back for a 3-6, 6-3, 6-3 victory.

“Losing that first set, I got myself pumped up,” Disch said. “I didn’t want to lose to Kasey in two sets. I wanted to at least get three, and I did it. I kept my momentum in the third set, and I got him.”

Disch’s tournament run ended in the next round, when he lost to Falmouth’s McCarthy, 6-0, 6-0.

“I’ve played with Brendan McCarthy — I knew what was coming,” Disch said. “I was trying to at least get a couple games. I didn’t get that, but I was proud of myself for making the (final) 16.”

Matt DiFilippo — 861-9243[email protected]Twitter: @Matt_DiFilippo