Conrad Roberts tees off on the third hole during the second round of the LAGA city tournament on Sunday, July 8, 2012, at Alvamar CC. In the background is Michael Rack.

It took a pressure putt on the 18th green to make it happen, but Conrad Roberts added another Lawrence Amateur Golf Association city championship trophy to his collection Sunday at Alvamar.

Playing in the same group with Michael Rack, who tapped in a par putt to finish even for the two-day tournament, Roberts nailed a roughly 20-foot putt to beat Rack by a stroke and earn his sixth LAGA title.

“This year was the toughest for sure. It was a really good-quality field,” said Roberts, who won five straight championships between 2006 and 2010, and didn’t play in 2011.

The former Kansas University golfer held a three-stroke advantage on Rack entering the second round at Alvamar’s private course, and Roberts extended it to four entering the back nine.

Said Rack of the front nine: “I shoot 1-under and lose ground.”

But Rack quickly found himself back in the hunt when Roberts got off to what he considered a horrid start on the back nine — relinquishing his lead after just three holes by going bogey, double bogey, bogey.

“Mike just played solid, making pars, and he’s gaining ground,” Roberts said. “That’s not how it’s supposed to work. I was kind of giving back to the guys at that point, and that was not part of my game plan at all. I was kind of digging myself a hole.”

Rack, who harnessed positive momentum by holing out a 50-yard birdie on No. 5, said it wasn’t until after the 12th hole, when he and Roberts were tied, that he felt like he had a shot to win his first city championship.

“Just like that, we’re tied with six to go,” the runner-up said. “Wow. It’s game on.”

The pair remained all square entering the 16th hole. Roberts knew he would need at least one birdie on the final three holes, and he got it on the 16th with a good tee shot, a dead-on approach from 90 yards out and an easy birdie putt on the par 4.

Though Rack was clean on the last three holes, managing a par on each, Roberts’ long putt on 18 sealed it.

“Conrad made a great up-and-in to win by one,” Rack said.

William Gantz, who works at Alvamar, wasn’t far behind the two leaders. He shot 1-under in the second round to finish 3-over. After Gantz shot 34 (2-under) on the front nine, he thought a duplicate number on the back would put him in the mix for the city title. But because he played in the group in front of Roberts, Rack and Kyle Ritchie (fourth place, 5-over), all he could do was guess.

“You don’t know where you’re at,” he said of his place, in relation to the leaders. “If you take care of your own business, then you see what happens.”

When he got to the clubhouse and saw he took third, he didn’t feel too bad.

“I’ll take it,” Gantz said with a grin.

Former KU golf coach Kit Grove finished fifth in the men’s championship flight at 11 over. Justin Hohl and Greg Sharp tied for sixth place at 14 over, Josh Williams took eighth at 15 over, and Matt Bellemere and Steve Randall tied for ninth at 16 over.

The most competitive flight at the 2012 LAGA event turned out to be the women’s field. It took a three-hole playoff for Holly Richey to take the title from Jettie Bezek. The two were tied at 173 after the second round, forcing the extended play.

On the first playoff hole, both Richey and Bezek finished with a bogey. They played it a second time and tied again, with a pair of pars. Finally, moving on to hole No. 2, Richey birdied to beat Bezek’s par.

In the seniors championship flight, Dennis Gisel (148) moved from fifth place to first with a 71 in the second round. He finished two strokes ahead of Mike Grosdidier, who led after the first round. Bob Bezek took third, finishing a stroke behind Grosdidier.

In the three-player super seniors championship flight, a 158 for Chris Davis allowed him to beat runner-up Galen Smith by two strokes and third-place John Emerson by three.

Ryan Scott (160) won the men’s first flight by eight strokes. John Butler and Gary Fister tied for second.

Eight strokes also was the margin of victory for James Stansell (155) in the seniors first flight. Mike Beaton finished second.

In the super seniors first flight, Mike Richey (167) held off runners-up John Nalbandian and Chris Peter by five strokes.

In the men’s second flight, Michael Farve (186) beat Tom Keegan by six strokes.