The DeMatha baseball team is focused on the postseason. (Mark Gail/WASHINGTON POST)

Saturday can’t come – and go – fast enough for DeMatha’s Sean O’Connor. The fourth-ranked Stags coach is excited to jump into the postseason, with either DeMatha or No. 2 St. John’s holding the top seed in the Washington Catholic Athletic Conference playoffs.

But with the commencement of Saturday’s single-elimination quarterfinal round comes the potential that one bad day can sink a good regular season.

“I’ll be a nervous wreck Saturday,” O’Connor joked following the Stags’ win against No. 9 Riverdale Baptist on Tuesday. “Anybody can beat anybody in seven innings and a one-and-done situation, and nobody wants to be on the wrong end of that. Hopefully our guys will rise to the occasion, but in that scenario, you just want to get to [the semifinals on] Monday.”

The semifinals are a best two-out-of-three series.

O’Connor’s anxiety could be heightened by DeMatha’s recent trend of briefly relinquishing early leads before storming back for victory. It happened Tuesday, when the Stags saw two home runs erase a 2-0 lead before rallying for a 7-5 win behind Bradley Keith (3 for 4 with a homer and three RBI) and the pitching of Kevin Fitzmaurice.

It also happened three other times in the past two weeks, when DeMatha notched comeback wins against WCAC rivals O’Connell and Good Counsel and in a non-league game against No. 7 Georgetown Prep.

These key victories have been symbolic of the Stags’ turnaround from last season, when they finished 6-10 in the WCAC and lost in the quarterfinals to second-seeded Paul VI Catholic. This year, the senior-laden Stags are 12-3 in the league entering Wednesday’s regular-season finale against Gonzaga and are primed to contend for their first WCAC crown since 2008.

“I think this is our best chance to make a postseason run with the talent we have and resilience we’ve shown,” said Fitzmaurice, who hit a grand slam to spark DeMatha to its win against Georgetown Prep. “It’s all about finding a way to win, and we’ve shown that we can pick up each other up and do that if we need to.”

Raiders out for revenge

Stuart will try to break a 17-game losing streak in the Yorktown series when the Raiders play at the Virginia AAA National District front-runners Wednesday night, with senior ace Jack Gomersall on the mound.

“Jack is probably 0-3 against them in the past two seasons, so he owes them one and we owe them one,” Stuart Coach Randy Lightle said.

If the Raiders (12-4, 8-2) are to pull the upset, they likely would do so with pitching, with Gomersall, seniors Chris Clayton and Jacob Kniatt and junior Nick Young having paced the team this season.

They have helped the team compile a 2.97 ERA and compensate for an average defense and a top-heavy batting order that’s hitting about .370 in the first few spots, thanks in part to senior first baseman Casey Duncan, and about .180 thereafter.

The Raiders lost one regular to grades and another who returned home to the Dominican Republic, so those losses weakened the batting order and defense. But not the pitching staff.

“We talk to the kids all the time about we just have to get better defensively and we have to hit,” Lightle said, “because the pitching has been carrying us.”

Saxons finally get best of Stone Bridge

Langley scratched for a run in the first inning Tuesday night against Stone Bridge sophomore ace J.B. Bukauskas and made it stand in a 1-0 road win, just the Saxons’ second victory in the last 15 games in the series.

Senior Thomas Dungan doubled a full-count pitch in the first for what would be Langley’s only hit of the game. Sophomore courtesy runner Antonio LaManna took third on a wild pitch and scored on a two-strike groundout by senior Cal Jadacki.

Langley senior Joseph Aulisi threw a three-hitter with eight strikeouts and no walks and did not allow a baserunner past second. Bukauskas struck out 13 and walked two.

LaManna is a recent call-up from the junior varsity team, and his speed and instincts were integral Tuesday.

“The ball he scored on when Cal put it in play was a low line drive, and he did a great job of reading it off the bat,” Langley Coach Kevin Healy said. “A lot of kids would have frozen, but he read the angle and took off. If he didn’t make that quick of a read, we probably wouldn’t have scored.”

Langley (11-6, 8-3 AAA Liberty District), a Northern Region semifinalist last season one win short of a state tournament berth, has a better record now than it did at this time a year ago despite losing 14 seniors off that team.

“They’ve had a lot of confidence this whole season,” said Healy, whose team hosts No. 1 Madison on Friday. “It’s not like they came in overwhelmed by the moment.”

Stallions join Patriot District logjam

South County (10-6, 6-4) has won six of its last seven games to further jam the Virginia AAA Patriot District. The Stallions’ only loss during that time was to No. 3 Lake Braddock.

“We’re just starting to play better and we’re getting some breaks we didn’t get earlier in the year,” said first-year Coach Robbie Smith, who had been an assistant in the program since South County’s inaugural season in 2006. “We’re not dominant in any one category. We’re just playing better.”

One player who has been dominant is senior catcher Keaton Tettelbach, who is batting .500.

Entering games Wednesday night, there were three teams with 6-4 records in the Patriot and another at 5-5. The top two teams in the district will earn automatic region tournament berths.

The Post Top 10

Madison, on a 15-game winning streak, will try to hand Coach Mark “Pudge” Gjormand his 300th career victory at home Wednesday night against South Lakes. . . . With regular-season closing WCAC victories against St. Mary’s Ryken and Gonzaga, St. John’s can enter the league tournament on a 13-game winning streak against conference foes. . . . Lake Braddock has a three-game lead in the Virginia AAA Patriot District. . . . Paul VI’s five WCAC losses have come by a combined 48-4 score. . . . North County enters the rankings this week on a five-game win streak and atop the Anne Arundel County standings. Matt Prince is batting a team-high .426 with 19 RBIs for the Knights, who will close the regular season next week with tests against Old Mill and Huntingtown. . . . Georgetown Prep’s only local losses have been to Paul VI and DeMatha. . . . Winners of nine in a row, Gaithersburg has averaged almost nine runs during its streak. . . . Riverdale Baptist, top-ranked two weeks ago, has dropped three of four. . . . The only loss for Potomac Falls since March 13 came Saturday when visiting Bridgeport (W.Va.) beat the Panthers on an inside-the-park grand slam in the eighth inning.

1. Madison (15-1) LW: 1

2. St. John’s (16-3) LW: 2

3. Lake Braddock (13-3) LW: 4

4. DeMatha (17-7) LW: 6

5. Paul VI Catholic (17-7) LW: 5

6. North County (13-3) LW: NR

7. Georgetown Prep (19-7) LW: 8

8. Gaithersburg (14-2) LW: NR

9. Riverdale Baptist (22-4) LW: 3

10. Potomac Falls (13-2) LW: 10

Dropped out: No. 7 Maret (17-4), No. 9 Oakland Mills (14-2)

Bubble: Battlefield (15-2), Centreville (12-2), Atholton (12-3)

(Records through Tuesday)

Related: Potomac Falls ace Pearson dominates Valley once again | Photos

Related: DeMatha outlasts Riverdale Baptist

Schedules: Baseball | Softball

Standings: Baseball | Softball

Statistical Leaders: Baseball | Softball