Ralph Dalton says without hesitation, whenever asked, that he is not Patrick Ewing and cannot replace him.

Even so, Dalton -- Georgetown's fifth-year senior center -- scored a career-high 18 points and pulled down a career-high 15 rebounds in 32 minutes playing time last night before a crowd of 8,188 at the Patriot Center to lead the No. 6-ranked Hoyas to a 75-63 victory over George Mason in the first meeting ever between the two schools.

It was the 300th career victory for Georgetown Coach John Thompson, who said he didn't even realize he was one short of the milestone until he was told earlier yesterday. "When I quit, I'll count how many games we've won," he said.

Thompson had Dalton, among others, to thank for the Hoyas' first mainland victory of the season. "I was saying to (assistant coaches) before the game that I probably should be playing Ralph more than I did (in two games in Hawaii)," Thompson said. "I think people are going to find out Ralph is better than they thought."

Georgetown led by only 30-28 at halftime. But the Hoyas stepped up defensive pressure after intermission and scored the first 12 points to pull away, 42-28.

George Mason Coach Joe Harrington elected to go without freshman point guard Earl Moore through those first five minutes of the second half. And Georgetown's defense forced the Patriots into five turnovers, two timeouts and a charging foul.

Ricky Wilson and Rob Rose, anything but point guards, couldn't solve the Hoyas traps.

Dalton had started the half with a baby hook shot for a 32-28 Georgetown lead. And Rose, normally a 6-foot-6 forward, threw a pass away for one turnover. Michael Jackson hit a jumper to make it 34-28. Wilson, taking his turn at the point, committed a charging foul, and Rose made another turnover preceding a basket by Reggie Williams that increased Georgetown's lead to 36-28.

Harrington called one timeout only 1:52 into the second half. But on the ensuing possession, Wilson was trapped into committing a 10-second violation, and shortly thereafter, Horace Broadnax sank a jumper for 38-28.

Mason called another timeout with 17:19 to play when Wilson couldn't get the ball in bounds.

A steal by David Wingate led to another basket by Broadnax, and a three-second violation allowed Georgetown to get the ball in to Dalton, who grabbed an offensive rebound and scored for 42-28.

Finally, nearly five minutes into the half, the Patriots (2-2) got a 16-foot jumper from Wilson, for two of his game-high 19 points.

Mason played Georgetown evenly the rest of the way, but couldn't get closer than 10 points.

"I am proud of our guys for the way they hung in there," Harrington said. "We improved tonight, but three things hurt us: their spurt at the start of the second half, Dalton's stick backs, and some long shots at times when they really hurt."

And Harrington wasn't about to forget the 23 turnovers his team committed. "We lost the ball too much; it's a game of possession. You can't lose the ball 23 times and expect to win."

Besides Dalton's performance, which also included two assists and four steals, Georgetown (3-0) got 17 points and 11 rebounds from Williams, 17 points and three assists from Wingate, nine points from point guard Jackson and eight points in 12 reserve minutes out of freshman Charles Smith from All Saints High School.

"That little Smitty is something, isn't he?" Thompson said of the player he recruited primarily as a defensive specialist.

George Mason placed three players besides Wilson in double figures. But Brian Miller, whose jump shots produced eight points in the first half, had only a layup thereafter.

One of Miller's jumpers gave Mason an early 8-3 lead, and another pulled the Patriots within two at the end of a first half Thompson later characterized as "wild and exciting."

It's the kind of game Thompson doesn't like to get into in December, while still trying to get a reading on his team.

"I like to play my younger players more, but my competitive instincts took over," Thompson said. "When you get in a war, you go to win."

The first half was so hot, Thompson was uncharacteristically calm with his team at halftime.

"They showed us no respect," Thompson said in his own way of complimenting George Mason. "Joe's going to have a good team soon. They played Maryland with pride (in an 81-80 loss) and they played us with pride."

But with five experienced players on the floor at the outset of the second half, Georgetown did what it did best last season: press.

Even without Ewing, the Hoyas can roll off a dozen straight points. "We have a way of doing that at times," Thompson said.