NEW YORK, FEB. 5 -- While injured Eamonn Coghlan helped with the television commentary tonight, fellow Irishman Marcus O'Sullivan cemented his position as the new chairman of the boards.

O'Sullivan ran away from Great Britain's Peter Elliott in the stretch to win the prestigious Wanamaker Mile at the 81st Millrose Games in a creditable 3:56.89.

It was the second Wanamaker triumph in three years for O'Sullivan, the world indoor champion who was a close second to Coghlan here a year ago.

Abdi Bile, the world outdoor champion from Somalia, was not inspired by the presence of George Mason teammate Kevin Black as the pacesetter. Although Black took the field through the first half in the prescribed 2:00 before dropping out, Bile ran in last place most of the way and never challenged, finishing fourth in 3:59.71.

The third-best mile of the night was turned in by Charles Cheruiyot, a Kenyan running for Mount St. Mary's, who set a meet record of 3:57.95 in the IC4A Mile. One could only have wished Cheruiyot had been in the Wanamaker field.

There were other moments to remember, not the least of them the Madison Square Garden crowd of 18,126 singing the National Anthem when the vocalist was betrayed by an inoperative microphone. It was a far cry from the usual Garden practice of drowning out the anthem.

In a sadder vein was the sight of four runners lapping Peter Snell, the double Olympic champion of 1964, as at age 49 he plodded home eighth and last in the Masters Mile in 4:53.63. Web Loudat, 41, was the winner in 4:20.04 with Frank Shorter, 40, third in 4:21.95 and Jim Ryun, 40, fifth in 4:29.60.

Greg Foster won the high hurdles for the sixth time in the Millrose Games. The only surprise was the identity of the man who was a close second -- Arthur Blake of Florida State.

Renaldo Nehemiah, the world record-holder trying to return to past glory after a fling at football, was a badly beaten fifth. Nehemiah got out ahead of Foster, but was trailing before they cleared the first of five hurdles.

Actually, Nehemiah's fate was foreordained by his performance in the semifinal. He got off to an excellent start, only to be overhauled and beaten by Cletus Clark, the third man in the final.

Foster's time of 7.07 matched what was the world indoor best when Nehemiah clocked it here in 1978. Nehemiah, whose current world indoor record stands at 6.82, was nowhere near that time tonight, managing 7.22 in both semifinal and final.

"I'm happy with the win, but not with the time," Foster said. "I was hoping for a faster race. My goal for the indoor season is to break the 55-meter record."

Nehemiah said, "I lost my momentum and balance by being airborne. I'm running up and over the hurdling plane. I used to be very explosive over the hurdles. Obviously, I have work to do."

Jackie Joyner-Kersee set a meet record of 22 feet 8 1/2 inches in the long jump, two inches shy of her U.S. indoor record and far from the world mark of 24-0 1/4 established at Madison Square Garden last winter by Heike Drechsler of East Germany.

Joyner-Kersee obviously was the victim of too busy a week. Thursday, she received the Flo Hyman Award from President Reagan and also was named the outstanding woman athlete of the year by Track and Field News.

Gwen Torrence extended her string of sprint victories to 34, including preliminaries, by overcoming a false start to win the 55-meter dash in 6.64. After the triumph, her third straight in the Millrose meet, Torrence bounded back down the track in unrestrained joy.

The runner-up in 6.71 was Evelyn Ashford, never a Millrose champion. Sheila Echols was third in 6.73. Pam Marshall, one of the favorites, was badly outdistanced in 6.98.

"The streak doesn't mean that much to me," Torrence insisted. "I learned from Edwin Moses not to put a lot of emphasis on the streak, so I won't be disappointed when it ends."

Antonio McKay, bumped off balance the first time he tried to get past pace setter Michael Franks in the 400 meters, made it handily on his second try and won the event for the third straight year in 47.00, matching his indoor record for a 160-yard track.

Ian Morris of Jamaica came from far back to retain his 600-yard title in 1:08.63, a meet record, while Sammy Koskei of Kenya captured the 1,000 meters for the fifth time in six years, cruising home in 2:21.30.

Diane Dixon, competing under new coach Russ Rogers after 11 years as Fred Thompson's pupil, showed she is still one of the smartest runners on the boards. Taking the lead early and forcing Valerie Brisco to run most of the race on the outside, Dixon captured the women's 400 in 52.48.

Ken Lowery also used his head as much as his legs to win the 500 meters in 1:01.74, a Garden record. While Mark Everett was overhauling pace setter Mark Rowe on the outside down the stretch, Lowery took the inside route to beat both of them.

Brian Cooper, whose best credentials derive from his long jumping, was a surprise winner of the 55-meter dash in 6.12 seconds.

Defending champion Lee McRae was ousted in the semifinals, along with Calvin Smith, the world outdoor champion at 200 meters, and Mark Witherspoon.

The women's 55-meter hurdles produced an unbelievably close finish, with the first four separated by only two-hundredths of a second.

The winner was Rosalind Council in 7.57. Defending champion Lavonna Martin, in second place, and Canadian Julie Rocheleau, in third, were timed in 7.58. Kim Turner McKenzie, the Olympic bronze medalist, was fourth in 7.59 and Stephanie Hightower-Leftwich, a five-time Millrose winner, finished fifth in 7.65.

Tim Lewis captured the mile walk in a world indoor best -- the event is not recognized by the IAAF -- of 5:33.53. That trimmed more than four seconds off the mark of 5:38.2 established by Lewis a year ago at the Los Angeles Forum.

Although Michael Greene brought Navy from fourth place to second with a strong anchor leg, the Midshipmen (3:21.96) dropped a mile-relay decision to Georgia (3:20.97).