As an early loss to Dartmouth made clear, nothing will come easy in Harvard’s quest for a fifth straight Ivy League title. Visiting 0-4 Brown on Friday, the Crimson cruised to a double-digit lead in the first half — and promptly lost it in the second. Harvard needed a buzzer-beating basket to force overtime and eked out a 76-74 win, but questions abound heading into Saturday’s showdown at Yale.

The Crimson led by as many as 13 points until a Brown run cut the halftime gap to six. Coming out of intermission, Harvard’s starters committed turnovers on six straight possessions, allowing the Bears to take their first lead of the game and complete a 20-4 run. Neither team led by more than five points for the final 24 minutes of play.

Down the stretch, Friday’s game became a battle of starring guards. Brown point guard Tavon Blackmon played the best game of his career, shattering his previous high with 25 points on 7-12 shooting to go with nine assists. The sophomore took advantage of broken plays for some of his early points, but by the end of the game he was breaking down Harvard’s set defense himself.

Blackmon led the Bears’ offense, in flux after leading scorer Leland King’s departure, to 1.07 points per possession against the Ivy League’s stingiest defense. His spinning layup beat the shot clock to tie the game at 57-57 late, and his contested floater over Siyani Chambers gave Brown a lead in the final minute of regulation. “I think he’s really growing,” Brown coach Mike Martin said. “When we recruited him, we thought he was a guy who could be the best point guard in our league.”

But Blackmon’s buckets were often answered by Crimson star Wesley Saunders. The senior ended Harvard’s eight-minute scoring drought that spanned halftime; later in the half, he beat the shot clock with a hot-potato three-pointer that mirrored an early-season dagger against Boston University in both execution and game state.

And he made a game-saving shot at the end of regulation. After Blackmon split a pair of free throws with eight seconds left to go ahead 64-62, Saunders took a handoff from Chambers in the run of play, drove into the lane and missed an awkward floater — but he recovered to corral the rebound and lay it in at the buzzer, forcing overtime.

He added five points in the extra period, and the Crimson made free throws and handled Brown’s pressure well enough to survive. Saunders scored 33 points — most for a Harvard player since Drew Housman did the same at Princeton in 2007 — to go with 10 rebounds and three steals. More importantly, he was seemingly Harvard’s only offense for long stretches, finishing with a 41% usage rating in 40 minutes.

Thanks to Saunders’ heroics, the Crimson remain one game behind unbeaten Yale, a gap they can close in New Haven on Saturday night. Three more thoughts from the Pizzitola Sports Center:

1. Friday in February is a tough time for tinkering. After keeping a fairly stable rotation through much of non-conference play, Harvard coach Tommy Amaker has become more creative with his lineups in recent weeks. Eleven players saw the floor in Friday’s first half alone, and the Crimson’s leader in minutes was Agunwa Okolie. After Steve Moundou-Missi fouled out in regulation, and with Kenyatta Smith still sidelined due to injury (Smith was dressed Friday but did not play), Harvard played small for most of the stretch run, even on a couple possessions in which Brown had big lineups.

Most puzzling was the usage of Siyani Chambers. The point guard has had a rough season statistically, but Harvard has been much better with Chambers on the floor, especially on offense. Yet he sat for more than seven straight minutes in the second half of a one-possession game. “It was a tough night for him with Blackmon,” Amaker said. “We made some switches to try to get different guys on [Blackmon], bigger guys.” (Down the stretch of regulation, Amaker also sat Chambers for only defensive possessions — which is more reasonable, if still debatable, especially since Brown’s shooting guards wouldn’t make cross-matching too dangerous.)

Harvard survived that stretch Friday, coming out ahead 14-11, but all evidence suggests benching Chambers is a losing bet. Juggling Harvard’s frontcourt is a true challenge for Amaker, between injuries, varying skill sets and foul trouble (which figures to be a problem against Yale), but Chambers and Saunders should simply play as much as possible.

2. The Bears could have sealed the game with better defensive rebounding. Brown has been roughly average on the glass this season, but it got killed by the Crimson, surrendering 20 offensive rebounds on 38 opportunities. Jonah Travis took the most advantage, grabbing five missed shots off the bench. Harvard’s two biggest plays of the game — a shooting foul drawn by Travis on the penultimate possession of regulation and Saunders’ game-winner — both came on second chances.

3. Brown is a really good 0-5 team. Even after losing King for the season, the Bears haven’t gone into hibernation. Despite playing the league’s toughest schedule to date, Brown went to the wire at Yale and has been ahead or tied in the second half of its last four games. Blackmon hasn’t yet shown consistent greatness, but if he and Cedric Kuakumensah (15 points, four blocks) can play something like they did Friday, the Bears will win a few of their remaining games (possibly starting Saturday against Dartmouth).

“I like the way we fought, and I like the character of our team,” Martin said. “I really don’t think we’re far away. I know our record would tell you we are, but I like the fight we have in that locker room.”