NEW YORK--The Harvard football team, down 17 points early in the second half, bounced back to steamroll Columbia, 49-17, here this afternoon in front of 7921 at Lawrence A. Wien Stadium at Baker Field.

The same Crimson offense that gained 54 total yards in the first half--and just eight on the ground--ripped apart the Lion defense after a field goal gave the hosts a 17-0 advantage at 6:43 of the third quarter.

Lamont Greer, Brian White, Rufus Jones, Robert Santiago, Santiago again and Brian O'Neil scored touchdowns in just over 15 minutes in the third and fourth quarters to spoil the debut of Columbia Coach Jim Garrett and to give Harvard its biggest point total since it spanked the Lions, 57-0, in 1973.

The loss extended Columbia's non-winning streak to 15.

Garrett, who has promised to reverse the dismal football tradition in Gotham, brought his troops out on a wave of enthusiasm in the first half.

Columbia took over on the Harvard 41 after a short Rob Steinberg punt, and the Lion linemen took over.

Chirico went up the middle on a well-exucuted trap for a quick 22-yard gain. Two plays later, Santos scrambled from the 14 to within inches of the Harvard goal line, and Chirico took it in from there. The extra point put the hosts on top, 7-0.

After the kickoff, three Harvard plays and a 44-yard Steinberg punt, the Lions took control again, this time at their own 23.

Santos picked the Crimson defense apart, connecting on six strikes for 83 yards and a touchdown.

The senior quarterback from Edison, N.J., struck Homer Hill all alone in the middle of the end zone at 11:58 for the second Lion score to top the hosts' impressive eight-play, 76-yard drive.

The Crimson mounted its first serious threat of the afternoon, but a White fumble in the Harvard backfield stymied the drive at the Columbia 29-yd. line.

The two teams exchanged turnovers as the Lions' momentum slowed and the Crimson offense began to adjust to the new Columbia defense introduced by Garrett.

The Crimson miscue was particularly costly as White floated a pass intended for split end Joe Connolly into the arms of Lion defensive back Ron Hartz.

But time and the blistering heat took their toll on the Lions, who wilted in the last 25 minutes.

The first half was a statistical nightmare for the Crimson. Columbia engineered four times as much total offense as Harvard, including 103 yards rushing to Harvard's eight.

In the second half things got no better. The teams traded interceptions in their first possessions, and when Columbia took over on the Harvard 48 after a Dave Nickerson pickoff, the Lions began the drive that put the Crimson away, or so the partisan crowd thought.

Santos completed consecutive passes to Mark Milam and Hill to bring the ball to the Crimson 21.

A penalty pushed Columbia back to the 26, but Santos continued his mastery by firing a strike to Hill at the six.

The Lions just missed their third touchdown of the afternoon when a wide-open John Pennywell let a Santos flare pass slip away, but Chirico came back on the next play to bull the ball to the Harvard 1-yd. line.

The Harvard defense finally rose to the occasion, stopping Chirico cold on a crucial third down play. Larry Walsh then came in and booted a 21-yd. field goal to put the Lions up, 17-0.

Three scores behind, the Crimson finally woke up from a deep slumber. On the first play from scrimmage following the Columbia field goal, White lofted a 51-yd. pass to wingback George Sorbara, who leaped between a pair of earth-bound Lion defenders to make the grab.

Two plays later, White handed off to Santiago, who in turn gave the ball to Greer. On the reverse the sophomore speedster--playing hist first game in a Harvard uniform--turned around right end and pranced 15 yards into the end zone. A Steinberg point after and the Crimson trailed by 10.

The Crimson defense, led by middle guard Jerry Garvey, stopped the Lions on three plays and Chuck Shirey brought the ensuing Columbia punt back 36 yards. Columbia took a penalty on the play, moving the line of scrimmage to the Lion eight.

White kept on the option right, scampering into the end zone to cut the Columbia lead to three at 9:41 of the third period.

Less than four minutes later the Crimson took their first lead of the afternoon.

After the Crimson nailed the Lions on three plays, Shirey returned a short punt to the Columbia 46. Santiago took an off tackle play 11 yards, and two plays later Jones swept 25 yards into the endzone. The Steinberg PAT made it 21-17 with 1:37 left in the third period.

After kicking off, the Crimson again caged the Lions in three plays, got the ball back, and scored in quick succession.

On the second play from scrimmage, White lofted a 64-yard touchdown pass--the longest of his career--into the waiting arms of Santiago.

That score gave the Crimson, which had appeared hapless at the half, four touchdowns in less than eight minutes.

And Harvard wasn't through. After the Crimson defense bottled the Lions up on three plays for the fourth consecutive time, Santiago struck again.

This time the senior took a pitch from White and ambled six yards into the end zone untouched. The score at 4:31 topped a six-play, 40-yd. drive.

With just 1:04 left in the contest, O'Neil got his second score on a five-yard run, topping the final Harvard drive.

The Crimson, which had taken an enormous first half beating had come back and paid the hosts back times two.

THE NOTEBOOK: Harvard has now beaten the Lions seven straight times and nine of the last 10.