San Diego 28, San Francisco 24

SAN DIEGO (AP) -- Drew Brees hobbled off the field, his night's work done after throwing a touchdown pass and spraining his right ankle.

"It's always kind of a sigh of relief after the preseason is over and you look at your squad and we're relatively healthy right now," Brees said after the San Diego Chargers beat the San Francisco 49ers 28-24 in an exhibition finale Thursday night. "That's what you always strive for."

Brees, the NFL's Comeback Player of the Year in 2004, sprained his ankle while throwing a 13-yard touchdown pass to Kassim Osgood on the fourth play of San Diego's first drive.

"I'm embarrassed about it," Brees said. "It was a non-contact deal. But hey, I'm an old man at 26."

Cleo Lemon, San Diego's third-string quarterback, won it with a 13-yard scoring pass to Ruvell Martin with 19 seconds left. Lemon's second TD pass of the fourth quarter came shortly after Joe Nedney kicked a 27-yard field goal with 1:11 left to give the 49ers a 24-21 lead. That drive was keyed by fourth-stringer Cody Pickett, who had a 15-yard scramble and a 41-yard pass to Rashaun Woods.

Midway through the fourth quarter, Lemon was flushed all the way across the field and, throwing off-balance and across his body, hit tight end Landon Trusty with a 30-yard TD pass to tie it at 21-21.

San Diego right tackle Shane Olivea sprained his left ankle and outside linebacker Steve Foley was poked in the eye.

San Francisco's Alex Smith, the No. 1 pick in the NFL draft, threw his first TD pass of the exhibition season. San Diego backup Philip Rivers also threw a scoring pass.

But on opening day, Tim Rattay will start for San Francisco and Brees for San Diego.

Smith lost his starting job to Rattay after lackluster performances in the first two exhibition games.

Smith, who played at Helix High in nearby La Mesa before starring at Utah, was in for 23 plays over four drives, completing nine of 15 passes for 69 yards. He threw one interception and fumbled once, which he recovered.

Smith had a rough start. After two penalties against the 49ers, he was hit hard on two straight pass attempts that both fell incomplete.

Just before halftime, Smith rolled left and threw a 23-yard pass to Fred Amey to tie the game at 14.

"I was just trying to make plays, make something happen," said Smith, who bought more than 250 tickets for family members and friends. "We were trying to move the ball a little bit, get in a rhythm. We finally did that. We came together."

Coach Mike Nolan said Smith did a good job on the scoring drive.

"It started slow, as it typically does for Alex," Nolan said. "But he picked it up."

The 49ers (2-2), still mourning the death of guard Thomas Herrion on Aug. 21, will try to rebound from an NFL-worst 2-14 finish in 2004. They host St. Louis on Sept. 11.

The defending AFC West champion Chargers (2-2) open at home against Dallas on Sept. 11.

Brees' TD pass was set up by a 50-yard run by Michael Turner, the backup to LaDainian Tomlinson. Tomlinson was held out to avoid being injured, and All-Pro tight end Antonio Gates served the second game of his three-game suspension for failing to report to camp when the Chargers ordered him to.

Rattay came right back and led the 49ers on a drive capped by Frank Gore's 5-yard run to tie the game at 7.

On third-and-20 from the 49ers' 24 late in the second quarter, Rivers, Brees' backup, stepped up in the pocket and was almost sacked by linebacker Andre Carter. Rivers managed to get the ball to speedy rookie Darren Sproles, who zigzagged into the end zone to give San Diego a 14-7 lead.

San Francisco's Maurice Hicks scored on a 1-yard run midway through the third quarter to give San Francisco a 21-14 lead.

San Diego's Nate Kaeding missed a 53-yard field goal attempt in the first quarter, making him 3-for-7 in the exhibition season.