On an evening when the offense found its stride for the first time since the season opener, the San Francisco 49ers defense could not hold up its end in crunch time. 

Leading by four points with less than two minutes remaining in the fourth quarter, the 49ers allowed the New York Giants to drive 82 yards for a game-winning touchdown. San Francisco (1-4) lost in heartwrenching fashion on Sunday night, 30-27, to drop its fourth consecutive game.

After a couple rough outings, Colin Kaepernick bounced back in a big way in the Big Apple by completing 23-of-35 passes for 262 yards, two touchdowns and a 107.1 passer rating.

Here's what else we learned in the Week 5 road contest.

Late Touchdown Seals Fate in Wild Finish

Tied at 13 apiece at the tail end of the third quarter, the 49ers and Giants traded a flurry of scores until the final whistle. 

New York struck first with a 17-yard Odell Beckham Jr. touchdown to go up, 20-13. San Francisco responded on its ensuing drive when Garrett Celek hauled in his first career touchdown pass, a 5-yard strike from Kaepernick.

The Giants then regained the lead with four and a half minutes remaining in regulation on a 24-yard field goal. Kenneth Acker nearly picked off Eli Manning in the end zone a few plays earlier, but the 49ers defense still held New York to three points.

San Francisco again answered back, this time marching 80 yards in just seven plays to take its second lead of the game.

Anquan Boldin caught a 26-yard pass and Torrey Smith ran for 25 yards on a screen to set up a Pierre Garçon 2-yard touchdown run. Smith also drew a crucial holding penalty on the drive, one of three flags the wideout helped produce.

The lead did not last, as the Giants drove the length of the field in just under a minute and a half. Tramaine Brock came close to ending the game with an interception on a long Manning pass, but the ball hit the ground before the cornerback could gain possession.

Four plays later, Larry Donnell caught a 12-yard touchdown pass over the middle of the field for the game-winning score with 21 seconds left.

Kap Moves under Center

Entering the game, Kaepernick was just 4-for-10 passing from under center on the season, as most of his snaps came in the shotgun formation.

The 49ers switched things up a bit on Sunday night, lining Kaepernick up under center more and using play-action and bootlegs to keep the defense on its toes.

In the first half, Kaepernick completed 12-of-17 passes for 118 yards. He also rushed twice for 24 yards. The quarterback's best throw of the opening 30 minutes went to Smith on a rocket for a 17-yard gain.

After the break, Kaepernick continued to flourish under center. Trailing by seven points midway through the third quarter, the signal-caller led a 10-play drive spanning 88 yards.

Kaepernick and Boldin led the way, connecting twice on huge plays. On a third-down snap, Kaepernick threw an arching pass right into Boldin's hands for a 37-yard reception. Then at the goal line, Kaepernick found Boldin again on a rollout for a 3-yard touchdown. The score, which came with the quarterback under center, was Kaepernick's first touchdown pass since Week 2 in Pittsburgh.

Kaepernick went on to orchestrate two more touchdown drives, both spanning 80 yards. The season-high 27 points weren't enough, but it was still Kaepernick's best performance of the year.

Screens to Ellington Lead to Early Points

Geep Chryst gave Kaepernick a few confidence throws to begin San Francisco's opening possession of the game.

On consecutive downs, Kaepernick threw screen passes to Bruce Ellington. The first went for 30 yards on the left side of the field and the second went for nine yards on the right side of the field.

Those gains put the 49ers into Giants territory, where the drive then stalled outside of the red zone. Phil Dawson converted on a 43-yard field goal to give San Francisco a 3-0 advantage.

The score marked the first time this season the 49ers have put points on the board on their first possession. The 49ers ran several wide receiver screens on Sunday and three went for significant yardage. 

Red-zone Defense Stands Tall in First Half

After an Beckham reception of 49 yards put the Giants near the goal line on their initial possession, the 49ers defense kept New York out of the end zone on three straight plays.

On 3rd-and-1 at the 3-yard line, NaVorro Bowman and Antoine Bethea combined to stop Rashad Jennings short of the line to gain.

The defense surrendered a 2-yard touchdown reception to Shane Vereen early in the second before forcing another field goal later in the quarter.

New York was in position to score again with seconds remaining in the first half, but Brock recorded a clutch interception of Manning in the end zone to end the threat.

The "bend, but don't break" defense kept the 49ers within striking distance for the back-and-forth second half.

Tiller Makes Debut at Guard

As he did in the first four games of the season, Jordan Devey got the start on Sunday at right guard.

But after the offense's first possession, Andrew Tiller took over at the position for the remainder of the half. The 49ers promoted Tiller to the active roster on Saturday when they released cornerback Shareece Wright.

Tiller performed well in his second-ever NFL game action. Devey did return to the lineup in the second half to split time with Tiller. Who mans the right guard position moving forward will be something to watch.

Another player who got his first extended look of the year was Corey Lemonier, who started in place of Ahmad Brooks (bereavement). Rookie Eli Harold also garnered significant reps at the right outside linebacker position.