WEST POINT, N.Y. (AP) Army fullback Darnell Woolfolk was ailing at the end of the week, didn't practice on the eve of game day, and was gassed in the fourth quarter against Buffalo - just not enough to keep him on the sidelines.

Woolfolk scored on a pair of 1-yard runs and Army rallied past the Bulls 21-17 on Saturday as the Black Knights avenged their most painful loss from last season.

''We knew we needed to persevere. The offensive line had a great surge,'' said Woolfolk, who finished with 91 yards rushing on 21 carries. ''We worked hard collectively as a team and it showed in the fourth quarter.''

The victory for Army (2-0) avenged an overtime loss to the Bulls a year ago and extended the Black Knights' winning streak to five dating to last season.

''We played better fundamentally (in the second half),'' said Army coach Jeff Monken, whose defense held Buffalo to 2 yards rushing and 48 total yards after the break after allowing 117 and 264 in the first. ''We just gutted it out.''

Woolfolk's game-winner came on fourth down with 4:53 left after Kell Walker was ruled out-of-bounds before reaching past the right pylon on the previous play. It was Army's third conversion in four tries on fourth down.

''Our coaches trust us to go for it,'' said Army quarterback Ahmad Bradshaw, who finished with 147 yards rushing on 25 carries and scored once. ''It's amazing. It gives us confidence.''

Safety Jaylon McClinton forced a fumble by Buffalo quarterback Tyree Jackson and Andrew McLean recovered for Army midway through the third quarter with the Bulls (0-2) driving, and that helped turn the tide as the Black Knights converted to get back in the game. Woolfolk's plunge from inside the 1 narrowed the Buffalo lead to 17-14 on the first play of the fourth.

''We started fast, things were good,'' Jackson said. ''We just got to keep going. I think we kind of fell off in the second half. We couldn't get stuff going.''

Jackson scored on a 75-yard run and hit Antonio Nunn with a 48-yard touchdown pass to lead Buffalo. Jackson was unable to muster a comeback on the Bulls' final possession. He was sacked for a 14-yard loss on first down and the Bulls punted after three plays. He finished 9 of 16 for 193 yards passing.

Army sealed the victory moments later with a 15-yard run by punter Nick Schrage off a fake.

''If the Red Sea parts, I can go for it,'' Schrage said afterward about his clutch decision to take off instead of kick.

Buffalo coach Lance Leipold won six Division III national titles at Wisconsin-Whitewater and brought a .921 winning percentage as a head coach when he accepted the Buffalo job prior to the 2015 season. The Bulls went 5-7 in his first season but plummeted to 2-10 last year. But one of those victories was a come-from-behind overtime triumph at home against the Black Knights, Jackson's first career win as the Bulls starter at quarterback.

The Bulls scored two touchdowns in the final nine minutes of the fourth quarter in that one to force overtime as the 6-foot-7, 245-pound Jackson scored twice on the ground. He didn't wait that long on Saturday, busting the long scoring run early in the second quarter. He picked his way through the line and raced untouched down the right side before stumbling into the end zone to put the Bulls up 10-7.

Jackson followed that by hitting Antonio Nunn for a 48-yard touchdown after Bradshaw misfired on a fourth-down pass to give Buffalo a 17-7 halftime lead.

The Army defense pitched a shutout in the second half.

''We've shown some explosiveness, which is something we've been searching for for a long time,'' Leipold said. ''I'm pleased with the way we battled, but we've let too many opportunities get away from us.''

Army finished with 322 yards rushing, averaging just under 5 yards a carry, after gaining 513 against Fordham in a 64-6 home victory last week.

THE TAKEAWAY

Buffalo: Jackson is an emerging star, and with his size the Bulls can be competitive in the Mid-American Conference.

Army: The Black Knights have the run down pat but need to show some finesse in the passing game. Bradshaw overthrew a wide-open Jermaine Adams inside the 10-yard line on a fourth-and-2 play and also overthrew Kjetil Cline in the end zone. Both came in the second quarter and cost the Black Knights two scores. Bradshaw finished 2 of 8 for 17 yards.

UP NEXT

Buffalo hosts Colgate next Saturday night.

Army travels to play No. 2 Ohio State on Saturday.

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