OAKLAND, Cal. – On this day, the script ended early.

For a while, the Jaguars overcame that. And for a while, they had a chance to overcome the absence of not only their starting quarterback, but the NFL's defending rushing champion, too.

What happened instead was a struggling second-half performance, and what happened was the Jaguars (1-5) lost when they could have won, letting a two-touchdown lead slip painfully away in a 26-23 overtime loss to the Oakland Raiders (2-4) in front of 51,634 at O.co Coliseum on Sunday afternoon.

The loss was the second in overtime this season for the Jaguars, who have lost three consecutive games after a Week 3 victory at Indianapolis.

"We're consistent – that's for sure," Jaguars Head Coach Mike Mularkey said. "Unfortunately, it hasn't been on the positive side. It's on the side of not finding ways to win these games. It's my job to get these guys in position to do that.

"It's not been that way for this season. We've got to learn how to finish. Unfortunately, we have to feel like this as we all do until we learn how to hopefully take the next step. We haven't done that yet."

Raiders kicker Sebastian Janikowski kicked a 40-yard game-winning field goal two minutes, six seconds into overtime. That came two plays after Jaguars wide receiver Cecil Shorts fumbled trying to stretch a short pass into a first down.

The Jaguars led 20-6 in the second half, but with Gabbert and Jones-Drew out they managed just six second-half points and 54 total yards.

"We just have to come back into work and there will be a lot of peer-to-peer accountability," said Jaguars cornerback Derek Cox, who had an interception for a second consecutive game. "We'll look at the film and find a way to get better.

"We can't harp on this one too long. There's nothing we can do about it now. The mindset is get better and move forward."

Jaguars quarterback Blaine Gabbert, after throwing a 42-yard first-quarter touchdown pass to Shorts, left in the second quarter with a left (non-throwing) shoulder injury. Gabbert played three series following the injury, but Mularkey said it reached a point where it was unwise to have Gabebrt continue.

By the time Gabbert left the game, Maurice Jones-Drew – the NFL's leading rusher last season – was out with a foot injury.  Gabbert and Jones-Drew each spent the second half on the sidelines.

Jones-Drew wore a boot in the second half.

Chad Henne replaced Gabbert in the second quarter, struggling throughout the second half and finishing 9-of-20 passing for 71 yards and no touchdowns with no interceptions. He was sacked three times.

Gabbert completed 8 of 12 passes for 110 yards and a touchdown with a 123.6 rating, with his pass to Shorts giving the Jaguars a 7-3 first-quarter lead. Jones-Drew rushed for six yards on two carries, with Rashad Jennings replacing him and rushing for 44 yards on 21 carries.

The Jaguars finished with 209 total yards and 10 first downs, converting just one of a possible 15 first downs. The Jaguars had just two first downs after halftime.

Jennings' 5-yard touchdown in the second quarter gave the Jaguars a 14-3 lead, and came off one of two Raiders turnovers in the first half. Linebacker Russell Allen recovered a muffed punt at the 16, and Jennings scored three plays later.

The Jaguars extended the lead to 17-3 with a 50-yard field goal by Josh Scobee, a play that came three plays after Cox intercepted a deflected pass by Raiders quarterback Carson Palmer. Henne entered the game for the first time on that series.

The Raiders, trailing 17-6 at the half, pushed back in the second half, and after a 40-yard field goal by Josh Scobee made it 20-6, Palmer threw eight yards to Denarius Moore with 6:01 remaining in the third quarter.

The Jaguars pushed the lead to 23-13 following another Raiders turnover, with Scobee converting from 45 yards four plays after C.J. Mosley recovered a fumble at the Raiders 24. Defensive tackle Terrance Knighton forced the fumble with a first-down sack.

Janikowski's 31-yard field goal with 6:52 remaining cut the lead to seven, and Palmer tied it with a 1-yard sneak with 3:34 remaining. The Jaguars had three possessions after that, managing just one first down. They reached their 46 with a 26-yard swing pass to Jennings, but Shorts was called for offensive pass interference a play later, negating a scoring opportunity with 2:51 remaining.

The Jaguars didn't get a first down after that.

 "Today was very disappointing," Mularkey said. "We had plenty of opportunities, really, the whole game. We've got to find a way to do it."