With less than a minute remaining in the first half of Yale’s game at Penn this weekend, a cool breeze swept through Franklin Field, momentarily interrupting another August-like Saturday. A dark cloud suddenly obscured the glaring sun. The scoreboard read 7-7. And Mike McLeod ’09 was on the trainer’s table.

Given the foreboding conditions, it was easy to believe that time had run out on the perpetual summer that has been the 2007 Yale football season.

[ydn-legacy-photo-inline id=”13352″ ]

But after 60 minutes of regulation and three overtimes — punctuated by a steadfast goal-line stand by the Yale defense — the Bulldogs emerged bruised and humbled but still undefeated, a perfect 6-0, still candidates for the pantheon of all-time Yale juggernauts.

The 26-20 win — Yale’s (6-0, 3-0 Ivy) first at Franklin Field since 1990 — was due in large part to the defense, which intercepted Penn quarterback Brian Walker three times and limited first-team All-Ivy tailback Joe Sandberg to 3.2 yards per rush, bringing the unit to sixth in the nation in yards allowed.

“They’re up there with any defense we’ve played,” Walker said after Penn’s (2-4, 1-2) second straight overtime loss to the Elis. “They’re one of the toughest, they’re always in the right place, they don’t make too many mental mistakes and they tackle well.”

The defense also set up the game’s first score when cornerback Paul Rice ’10 intercepted a Walker deep ball to receiver Marcus Lawrence. Chasing the Penn sophomore at midfield, Rice noticed the underthrown ball a moment before Lawrence did and — with his momentum still carrying him into Yale territory — planted and made a diving catch at the Penn 46-yard line.

Rice was still celebrating when on the ensuing play McLeod sprinted through a gaping hole and left the nation’s No. 8-ranked rush defense in his wake.

On the second play of Penn’s next drive Walker tried to go deep to Lawrence again. This time he hit the receiver in stride, but so did cornerback Casey Gerald ’09, who popped the ball into the air, allowing ball-hawking safety Steve Santoro ’09 to make Yale’s second diving interception.

When McLeod runs of 16 and 13 yards brought Yale to the Penn 14, it seemed as if the 15,668 fans in attendance were in store for another day of defensive takeaways and McLeod breakaways. But three plays later kicker Alan Kimball ’08 missed a 39-yard field goal wide right — his first miss in nine tries — and Penn began to make successful adjustments.

After gaining 97 yards in the first quarter, McLeod was held to just 14 in the second quarter as the Yale offense sputtered.

“Obviously we knew we were going to have our hands full trying to stop them in the running game, and I think after the first quarter we acquitted ourselves really well in that area,” Penn coach Al Bagnoli said. “We forced them to make plays through the air, which at first they struggled to do.”

The Penn offense began showing life as well. The Quakers opened the frame with an 11-play, 53-yard drive that boosted the team’s morale and left Santoro with a separated shoulder. But the drive ended on a blown field goal attempt when a high snap forced holder Braden Lepisto, a wide receiver, to throw a desperate pass into the shins of pursuing defensive end Kyle Hawari ’09, who finished the game with 10 tackles.

After the teams traded possessions, Penn finally put together a scoring drive. On the strength of a fourth-and-one conversion by Sandberg and a pass interference call on Gerald, the Quakers had the ball within striking distance.

From the Yale 9 yard line Penn surprised Yale by calling for a halfback pass from Sandberg. His attempt at quarterback went better than Lepisto’s, as he was able to find Josh Koontz wide open in the end zone.

On the next drive McLeod left the game with a bruised right toe, leaving many fans wondering at halftime whether McLeod would be unavailable in Yale’s closest game this season.

When the third quarter began, McLeod was in the Yale backfield but the Quakers kept coming. Cornerback Chris Wynn picked off Matt Polhemus ’08 on the first drive of the second half, setting up a 43-yard field goal by Andrew Samson to give Penn the lead.

While the offense tried to figure out how to move the ball without McLeod at full speed, the defense kept the pressure on Walker and Sandberg, limiting the Quakers to just 72 yards on offense in the second half. Defensive tackle Joe Hathaway ’09 forced a fumble by Walker at the Penn 18 yard line to set up Kimball’s game-tying field goal early in the fourth quarter.

“This game goes to the defense,” Yale head coach Jack Siedlecki said. “The defense just kept playing through it all. When it was 10-7 late in the game, if the defense doesn’t play that way we don’t have a chance to come back and tie it.”

Safety Matt Coombs ’08, the hard-hitting special teams ace who was filling in for the injured Santoro, made Yale’s third interception after the Kimball field goal, but the offense failed to capitalize.

The offense fared better in overtime, opening its first possession with a 21-yard post-corner from Polhemus to Chris Denny-Brown ’08 that was reminiscent of a similar pass Polhemus threw to Chandler Henley ’07 in overtime against Lehigh last year. Two plays later McLeod charged into the end zone to give Yale the lead.

The touchdown could have proved to be the game winner if not for a questionable fourth-and-six pass interference call on Gerald during Penn’s first overtime possession. With the Yale sideline still roiling, Walker hit Lawrence with a five-yard quick slant that exploited Rice, who was protecting the outside.

After Samson hit a 23-yard field goal to put Penn ahead, Yale seemed determined to seize the game. Polhemus hit halfback John Sheffield ’10 along the right sideline for a fingertip catch and 19-yard gain. Two plays later on third down, Denny-Brown had a chance to win the game but could not corral Polhemus’ slant pass in the end zone.

The miscues continued on the field goal attempt when the usually steady Dan Sica ’08 skipped a snap to holder Richie Scudellari ’10, who managed to place it just in time for Kimball to get a foot on it without momentum.

“That was really amazing for Alan to have the awareness to know that we’re on the three-yard line and you can just punch it in from there,” Siedlecki said.

In triple overtime Denny-Brown atoned for his drop with a sterling 20-yard catch-and-run — his career-high ninth reception — to bring Yale to the five-yard line. Three plays later McLeod (147 yards rushing) got his third touchdown off a great lead block from fullback Joe Fuccillo ’08.

Polhemus was pressured into a bad throw on the two-point attempt, and Penn took over with a chance to win with a touchdown and two-point conversion.

Penn put Yale on its heels immediately with a 10-yard holding penalty by Rice and a completion to Koontz at the Yale one-yard line.

But the defense refused to yield, stopping three straight runs before Penn tried Sandberg on a pitch to the outside. He raced left but was met by Coombs and Brady Hart ’09 (11 tackles), prompting him to reverse field and attempt a pass. Receiver Nick Cisler caught it in the end zone, but the impromptu pass was called back because an ineligible lineman, William Milne, had wandered downfield.

On fourth-and-goal from the six, Walker tried throwing to Lepisto, who could not hang on with Gerald tight in coverage.

“By that point in a game like this, it’s already peeled away all the emotions,” nose guard and captain Brandt Hollander ’08 said of Yale’s final stand. “You’re so exhausted you can’t really get excited or get hyped up. You’re just playing with what you’ve got. I think that’s why it’s so special for us to get a stop like this. I think it speaks to the character of our defense.”

When it was all over, after 15 penalties — two of which were pass interference calls on him — Gerald lingered for a moment on the seat of his pants, looking as if were expecting to see a yellow flag.

“I did wait [to see whether there was a flag],” Gerald said. “But after that I didn’t feel like getting up.”