The City of York athlete was a clear winner in the shot put but was unhappy with his winning contribution of 19.03m.
The distance was short of the required Olympic qualifying standard of 20.45m although Lincoln still harbours hope of being granted a place in the squad for the European Championships in Amsterdam.
Lincoln said: “I was hoping for a bit further. I really honestly felt I had bigger distances in me today.
“I just wasn’t getting much height. It’s little tiny tweaks throughout the throw that all need to click at the same time to make it happen.
“I still have a long way to go on to the world stage but I believe it’s in me. If not this year, then certainly in the future.
“I have to break 20 metres. I felt fresh today but it just didn’t quite happen.
“I am pretty close to qualifying for the Europeans this year, within half a metre or so. Whether time runs out before I get it, I don’t know.”
Sheffield’s Karla Drew cursed hitting a succession of hurdles as she finished sixth behind sisters Tiffany Porter and Cindy Ofili in the 100m hurdles.
Drew, coached by Toni Minichiello a training partner of Jessica Ennis-Hill, neared her personal best as she stormed through her heat in 13.39sec.
However, the pressure of a 7,000-strong crowd told in the final in recording 13.58s.
Porter took gold just two hundredths ahead of younger sister Ofili in 12.91.
Drew said: “I was really disappointed in the final. I felt like I had run really comfortably in the heat and felt I could do better in the final but then I just kept hitting hurdles.
“I stood up straight out of the blocks and never really had a drive phase so just kept hitting the hurdles on the way down.”
In the main event of day two, James Dasaolu edged a thrilling battle as three sprinters dipped under ten seconds in a wind-assisted 100m final.
Dasaolu held off the challenge of James Ellington and CJ Ujah in 9.93 seconds to win his first British outdoor title and secure his place at the Olympic Games.
Ellington (9.96) put four up and down years behind him to secure the second automatic spot for Rio, while Ujah (9.97) must wait for a discretionary place when the GB squad is announced on Monday.
Despite the figures of Linford Christie, Dwain Chambers and Mark Lewis-Frances of yesteryear, this was the first time three British men had run under ten seconds in a national final.
“It was a tough race,” said Dasaolu, who recorded his personal best of 9.91s in the same lane at the Alexander Stadium in 2013.
“You couldn’t just come out there and expect to come top two.
“I knew that if I didn’t finish in the top two, my dream of going to Rio in the 100m was under jeopardy.
“When I ran the other sub 10 it was in the same lane - lane four - not that I’m superstitious.
“Going in when I saw I was in lane four again, I thought it was meant to be.
“It’s my second sub ten here so it’s positive all going forward.”
Sheffield athlete Lee Emanuel coasted through his 1,500m heat to make Sunday’s final in 3.44.29, while Leeds Beckett University student Laura Weightman also kept her Olympic hopes alive in the women’s event by nailing her place in the final in 4.16.74.
Pudsey and Bramley’s Alexandra Bell booked her spot in the women’s 800m showpiece as the third fastest qualifier.
Bell finished behind 35-year-old Jenny Meadows in the second heat but her time of 2.02.30 was enough to secure a fastest loser place.
Elsewhere, Asha Phillip won a third British 100m title while Morgan Lake and Holly Bradshaw earned victories in the high jump and pole vault respectively.