NEW HAVEN, Conn., March 26--Eliot House, undefeated in hockey since the war, kept its streak going at the expense of Davenport College yesterday with an incredible third period comeback that brought a 4 to 3 win and Harvard's only victory over Yale in the winter intramural competition.

First-line center Paul Birdsall, playing his last House hockey game, scored twice in 30 seconds--at 6:15 and 6:45 of the last period--to tie and then to win the game. Only a minute earlier, defenseman Clark Cowan had brought Eliot back to life with a rink-length dash that netted the second Mastodon goal.

Cavanaugh Brilliant

Goalie Tom Cavanaugh carried the load through the first two periods with a wonderful exhibition of shot-stopping. His nine saves in the second period, when Davenport was pressing hardest, were the only thing preventing a Yale runaway at that point. Six more in the final period--all difficult--held the desperate Eli team in check in spite of its last-minute strategy of pulling the goalie and using six forwards.

Davenport, opening with a rush that left Eliot far behind, scored first at 3:32 of the first period on a long screen-shot. Kent Eaton countered with an unassisted goal at 4:12, but two plays later Davenport's Joe Quinn scored from a faceoff in Harvard territory.

Davenport Has Edge

The second period was much the same as the first: Davenport's teamwork and speed gave it a definite adge over Eliot, whose backchecking and passing was sloppy. The only score came at 5:02 when Bill Dealy slapped in a rebound.

Birdsall's two last-period goals both came on one-man plays. Doug Bradlee passed to him at the Eliot blue line on the first, and he carried in from there to score; the second time, he poke-checked Davenport's left defenseman, grabbed the puck and scored on a shot almost identical to the previous one.