Answer based on context:

Coming off their loss to the Chargers, the Cowboys hosted the Denver Broncos at home for an interconference duel.  The Cowboys grabbed a 14-0 lead in the first quarter, with a 2-yard touchdown pass from quarterback Tony Romo to wide receiver Dez Bryant, followed by running back DeMarco Murray rushing for a 4-yard touchdown. The latter score occurred after a fumble by Broncos' wide receiver Eric Decker. The Broncos later got on the scoreboard, with quarterback Peyton Manning connecting on a 4-yard shovel pass to tight end Julius Thomas for a touchdown. Early in the second quarter, a 43-yard field goal by placekicker Dan Bailey gave the Cowboys a 17-7 lead. The Broncos then reeled off 21 unanswered points, with Manning adding two more touchdown passes &#8212; a 2-yarder to Decker and a 9-yarder to Thomas, followed by Manning rushing for a 1-yard touchdown on a bootleg play. A 48-yard field goal by Bailey at the end of the first half narrowed the Broncos' lead to 28-20. In the second half, the Broncos added to their lead midway through the third quarter, with Manning connecting on a 2-yard touchdown pass to wide receiver Wes Welker. However, the Cowboys subsequently began chipping away at the Broncos' lead, with Romo connecting on an 82-yard touchdown pass to wide receiver Terrance Williams. A 48-yard field goal by placekicker Matt Prater gave the Broncos a 38-27 lead, but the Cowboys further narrowed the Broncos' lead, with a 2-yard touchdown pass from Romo to Bryant (with an unsuccessful two-point conversion attempt). Following an intercepted Broncos' pass,  the Cowboys subsequently re-claimed the lead early in the fourth quarter, with Romo throwing a 10-yard touchdown pass to tight end Jason Witten, coupled with a two-point pass from Romo to Williams. The Broncos tied the game at 41-41 on their next possession, with a 50-yard field goal by Prater.  As the shootout continued, on the Cowboys' next possession, Romo connected on a 4-yard touchdown pass to wide receiver Cole Beasley to give the Cowboys a 48-41 lead with 7:19 remaining in the fourth quarter. Manning subsequently led the Broncos on a 9-play, 73-yard drive, which culminated with running back Knowshon Moreno rushing for a 1-yard touchdown to tie the game at 48-48 with 2:24 remaining in the fourth quarter. Two plays into the Cowboys' next possession, as the Cowboys were attempting a game-winning drive, Romo was intercepted by Broncos' linebacker Danny Trevathan at the Cowboys' 24-yard line just before the two-minute warning. On the fourth play of the Broncos' final possession, the Broncos were facing a 3rd-and-1 at the Cowboys' 2-yard line, after the Cowboys had exhausted two of their three team timeouts. Moreno earned a crucial first down after Manning implored him to go down before reaching the goal line instead of scoring a touchdown, which forced the Cowboys to burn their final timeout with 1:35 remaining in the fourth quarter. After three kneel-downs by Manning, Prater nailed the game-winning 28-yard field goal as time expired. With the narrow loss, the Cowboys moved to 2-3, and dropped to second place in the division.

how many points did the cowboys lead in the second?
17