The 3-8 San Francisco 49ers visited Soldier Field in week thirteen; in 63 all-time meetings, the 49ers held the lead 32-30-1, though the Bears won the last game in 2014 28-20. The Bears offense took on a defense featuring linebackers NaVorro Bowman, Aaron Lynch and Ahmad Brooks, who had a combined 12.5 sacks in 2015, including 6.5 by Lynch. Alshon Jeffery provided a size advantage over cornerbacks Tramaine Brock and Kenneth Acker, the duo having a combined 90 tackles, six interceptions, and 14 pass breakups. As a unit, the 49ers defense had struggled, allowing an average of 400 yards, 8.13 yards per pass (29th overall), 17 touchdown passes and a 100.5 opponent quarterback rating (also 29th-ranked). Despite these troubles, the 49ers had held the Cardinals, who had the league's best scoring offense, to just 19 points in week twelve. As for the Bears defense, the 29th-ranked rushing defense took on a running attack without Carlos Hyde. 49ers quarterback Blaine Gabbert had been improving, throwing for 318 yards against Arizona, while his top receiver Anquan Boldin had recorded 44 catches for 558 yards, 28 of which resulted in first downs. However, the San Francisco offense had the fewest points in the NFL with 152, a league-low 14 combined touchdowns, and a worst-ranked 31 plays of at least 20 yards. Meanwhile, the Bears had allowed an average of 17 points per game in the last five, the fourth-fewest in the league. Marquess Wilson, Eddie Royal, Antrel Rolle, Nick Becton, Jacoby Glenn, Antone Smith and Bruce Gaston were inactive. The Bears won the coin toss and elected to defer. The 49ers went three-and-out and punted; on the return, the Bears behaved as if Marc Mariani was returning on one side of the field, though Bryce Callahan actually returned it, and scored on the 65-yard play. However, a holding penalty on linebacker LaRoy Reynolds nullified the play. The Bears eventually scored a field goal with Robbie Gould's 40-yard kick. After the 49ers punted again, the Bears scored another field goal, this one being 51 yards. San Francisco subsequently punted, but scored on the second play of the Bears' next drive when Jimmie Ward intercepted Jay Cutler's screen pass for Alshon Jeffery and returned it 29 yards for the touchdown; the score remained tied after defensive tackle Eddie Goldman blocked the extra point. Chicago's next drive lasted into the second quarter, where Matt Forte took advantage of two consecutive 14-yard plays to score on a five-yard run. The 49ers scored on their drive with Shaun Draughn's one-yard touchdown run to tie the score. The first half ended with both teams tied 13-13. The Bears received the ball to start the third quarter, but failed to score when new long snapper Patrick Scales' snap was low and Gould missed the 40-yard kick. The next seven drives all ended in punts; the trend was broken when Ka'Deem Carey scored on a four-yard run, followed by San Francisco retaliating with Gabbert scoring on a 44-yard run. On the ensuing kickoff, Deonte Thompson's return went 74 yards to reach the 49ers' 28-yard line. On the drive, the Bears ran on each play, forcing the 49ers to use all three timeouts. With two seconds left, Gould's 36-yard field goal sailed wide left, resulting in overtime. The 49ers won the coin toss but punted, though the Bears were also forced to punt. On the first play of the next series, Gabbert threw a 71-yard touchdown pass to Torrey Smith to seal the win.. How many yards was the longest touchdown play?