Eamonn Coghlan left the rest of the field far behind with a 55.9 final quarter tonight and remained unbeaten in the Wanamaker Mile at the Millrose Games. Coghlan, timed in 3:54.40, became the first five-time winner of the event since Glenn Cunningham in the 1930s.

However, both Coghlan and Mary Decker Tabb, who won the women's mile in 4:25.27, were hampered by the absence of competition.

"I was disappointed that (Tom) Byers had to drop out of the race (with a pulmonary infection), because it took the competitiveness out of it," said Coghlan, who beat Thomas Wessinghage by 25 yards and John Gregorek by 30.

Carl Lewis leaped 28 feet 1/4 inch to win the long jump. It was the third time over 28 indoors for Lewis, whose world best is 28-1. All five of Lewis' fair jumps were better than 27 feet. Vesco Bradley took second with a personal best of 26-6 1/4, upsetting Larry Myricks (26-1).

Billy Olson won the pole vault at a Madison Square Garden record 18-6 3/4, then had the bar raised to 19 1/4. Although he came close on his third attempt, the first 19-foot indoor vault must await another night.

Fred Sowerby, 34, won his fourth Millrose championship by chasing down Tony Darden in the last strides of the 500-yard run. Sowerby, the track coach at Maryland-Eastern Shore, was timed in 56.04, second-best in the event's 18 years. Sowerby, whose specialty is the 600, was going the shorter route for the first time since 1974 because of lack of training time.

Greg Foster, with pro footballer Renaldo Nehemiah no longer forcing him into mistakes, overhauled Willie Gault in the last steps to win the 60-yard hurdles in 6.96 seconds. Foster's semifinal time of 6.92 has been bettered only by Nehemiah--five times.

Georgia's Heisman Trophy winner, Herschel Walker, received tumultuous applause from the sellout crowd of 18,232, but he was no match for Arizona State football star Ron Brown in the 60-yard dash final. Brown, who will turn pro before the 1984 Olympics if the offer is high enough, won in 6.11 to runner-up Walker's 6.17. Stanley Floyd, the winner the last two years, finished fifth.

Tyke Peacock beat Jerome Carter and Dwight Stones on fewer misses as all three cleared 7-4 1/2 in the high jump. Carter, 19, from Harford Community College in Bel Air, Md., was the only one close at 7-6 1/2. Navy's Leo Williams tied for fifth at 7-2 1/2.

The highly publicized high school mile provided considerable excitement, even if the winner, Miles Stahr of Carmel, N.Y., failed to lower Kevin Byrne's meet record of 4:08.0. Stahr, timed in 4:10.98, slowed considerably after a 58.5 opening quarter but three times successfully fought off attempts to pass by John Carlotti of Bernardsville, N.J. Rodney Giles of Maryland's Northern High was fourth in 4:16.25.

Another schoolboy, Clinton Davis of Steel Valley, Pa., won the 400 meters in 47.46 over a field that included five of the top six quarter-milers in the world: Bert Cameron, Mike Paul, Cliff Wiley, Darrell Robinson and Walter McCoy. Davis' time was a national high school best.

Floyd's wife, the former Delisa Walton, set a Garden record of 2:03.55 in winning the 800 meters. Robin Campbell, the pace setter until the final turn, faded to fourth in 2:04.40, also under the old Garden mark.

Louise Ritter set a Garden standard of 6-5 in the women's high jump, then failed in three tries at a world best of 6-7.

Stephanie Hightower scored a solid victory over Benita Fitzgerald in the women's 60-yard hurdles, clocking 7.44. Candy Young withdrew after suffering a severe cramp in the warmups.

Ray Sharp, a 23-year-old junior at Colorado State, established a world indoor best of 5:46.21 in the mile walk. He beat Jim Heiring, the United States' top-ranked walker, despite being forced to stop and replace a shoe after another competitor stepped on his heel.

Navy's quartet of Jere Fisher, Tracy Smyers, Lloyd Wright and Dallas Roper posted a front-running two-mile relay victory in 7:33.90 over Fairleigh Dickinson, William and Mary, Maryland and Penn State.

George Mason apparently breezed to a mile-relay victory in 3:17.00. However, the Patriots were disqualified because leadoff man Tommy Lovelace ran out of his lane and interfered with an Auburn runner, who fell.

Third-place East Carolina and fourth-place Adelphi also were disqualified, leaving runner-up Fairleigh Dickinson the only legal finisher. Only Villanova, with 3:15.96 in the last event, ran a faster time than the Patriots.