It was the wee hours of Christmas Eve, the man recalled yesterday, when he looked out the window of his Fort Washington home and saw two people in a pickup truck parked on his property, in an exclusive riverfront neighborhood known to police as a lovers lane.

The man said he told the pickup's occupants that his nicely wooded property along Riverside Drive two miles south of the Woodrow Wilson Bridge was no place for what they apparently had planned to do. An argument ensued, the man said, and the truck's driver wheeled around and hit the man with his Chevrolet pickup before speeding away.

The man, himself familiar with trespassing and brushes with the law, is convicted Watergate burglar G. Gordon Liddy.

Liddy, a former Nixon White House staff member who spent four years and seven months in prison for his role in the Watergate affair, was admitted to Southern Maryland Hospital. In an interview yesterday, Liddy said he suffered a broken left arm, broken rib, ruptured kidney and a torn ligament in his left knee. He said he expects to be released today.

Although Liddy was well known after the 1972 break-in at the Democratic National Committee headquarters in the Watergate complex, it seemed his fame was lost to the investigating Prince George's County police officer, who was a child during the height of the scandal and didn't know who Liddy was on Christmas Eve. The police report refers to the complainant as "Mr. Libby."

Liddy, 57, known for performing macho stunts such as holding his bare hand over flames, said, "A normal person would be dead, but as you probably already know, I don't fall into that category."

"I'm in tremendous physical shape," Liddy said. "I do 250 pushups a day and run four miles."

Liddy said the couple had parked in a place where a lot of lovers and drug users congregate. "I don't tolerate that sort of thing," he said.

Liddy said he approached the truck from the left rear, where he saw a man in his twenties with "fairly long, dirty blond hair." The passenger, a woman in her twenties, was a brunette "with a very pronounced nose," Liddy said.

With a police officer's billy club he often carries with him to chase trespassers, Liddy said he tapped on the window on the driver's side and told the man that he was on private property and to "get out of there."

The two men then had some words, Liddy recounted, and the driver pulled the truck forward, then threw the truck into reverse. But Liddy said he jumped out of the way and took out "his rear right tail light. It's an old FBI trick" to mark vehicles. "As you know, I was in the FBI," he said.

The truck made a U-turn and came barreling down a hill, Liddy said. The driver then turned the truck toward Liddy, he said. "I do not believe in taking back steps," said Liddy, who added that he crouched down as if he were a baseball batter ready to strike the oncoming truck with his billy club. "The truck won," Liddy said, knocking him 15 to 20 feet in the air.

Liddy was not able to provide police with the vehicle's tag number or a further description of its occupants. Cpl. Bruce Gentile, a police spokesman, said the driver, being sought by police, faces "a number of charges" including assault with intent to murder, hit and run, and simple assault.

The police officer who responded to the 12:45 a.m. call to Liddy's house was described by a colleague as a "rookie officer" and had no knowledge of Liddy's background.

Liddy recently appeared in an advertising campaign for WBMW, a Manassas radio station featuring new age music. In 1986 Liddy opened an academy in Miami that teaches protection of VIPs, hostage rescue and undercover work.