Kipketer, Kenyan-born but a naturalised Dane, clocked the season's best time in the 800 meter, finishing in 1min 42.27sec, to hold off Hezekiel Sepeng by a few meters. Kipketer was still within world record pace at the halfway mark but he had too much to do on his own from then on and finished 1.16sec outside. Sepeng set a South African record of 1:42.69.
Morocco's Zahra Ouaziz tried to shake off Szabo for much of the women's 3,000m, but the Romanian just bided her time. Szabo's sprint finish made sure the result was a repeat of the World Championships in Seville last week, finishing in 8:25.82, her second-fastest time this year.
In the jackpot competition, Kipketer and Szabo have won all six Golden League meets, and if they continue their streak at Tuesday's Berlin meeting, they will share the prize.
Bernard Barmasai, the controversial Kenyan steeplechase world record holder, also won his sixth race out of six last night, but the International Amateur Athletic Federation has kicked him out of the jackpot competition for saying he colluded with a rival to make sure he won in Zurich. If he wins the last of seven races, in Berlin, and is denied a share of the purse, he said he might sue the IAAF.
"You cannot be employed somewhere and get no salary," he said after winning. "I want to run good in Berlin and then afterwards do something."
Last night he proved he was best in his discipline, taking the lead at the halfway stage and building a 40-metre lead to finish in 8:03.08, the second-best time of the season. Fellow-Kenyan and world champion Christopher Koskei finished 4 seconds back.
Barmasai was only fifth place at the World Championships but said the Zurich scandal had cost him too much sleep and concentration.
The American women's 100-metre world champion, Marion Jones, was the only other athlete with a perfect five out of five performance before last night, but the sprinter has not recovered from the back injury suffered during the semi-finals of the 200m in Seville last week and could not run here.
In a great performance which had no impact on the Golden League, Morocco's Hicham El Guerrouj ran the second-fastest 3,000m in history, finishing in 7:23.09, just 2.42sec off the three-year-old mark set by Kenya's Daniel Komen.
The meeting featured 18 world champions from Seville. The main absentee was Maurice Greene, who is running in Glasgow over the weekend. In his absence, Canada's Bruny Surin, the silver medallist in Seville, won the 100m, in 10.04, edging the American Jon Drummond, but he was beaten in the 200m by Michael Johnson, who clocked 19.93.