Lisa Dobriskey and Helen Clitheroe gave British fans reason for cheer with impressive displays at the London Grand Prix Diamond League meeting.
Clitheroe knocked 24 seconds off her 5,000m best to grab a spot in the World Championships squad, named on Tuesday.
And 2009 world 1500m silver medallist Dobriskey won her first race of an injury-hit season, holding off team-mate Hannah England.
"It's not nice coming ninth or 10th - I know I'm better than that," she said.
"You just have to hold onto that belief. It's hard sometimes, but I have a great team around me who support me."
Clitheroe's decision to miss last weekend's British trials was vindicated as she come home second, behind Lauren Fleshamn of the United States, in 15 min 6.75 sec.
"There is a lot of pressure on us British athletes this weekend but this field was just what I needed," she said.
"I'm delighted, and really pleased with the finish, with being able to pick it up at the end of a PB run."
Dobriskey now believes she can pick up a medal in Daegu, South Korea at the end of this month.
"I would be silly to go there and not aim for a medal. I am working hard and I think it will come. I can turn things around quite quickly," she added.
The results were a fillip for GB head coach Charles van Commenee after he saw .
American Carmelita Jeter produced a blistering 100m run of 10.93 sec to hold off her Trinidadian rival Kelly-Ann Baptiste and Jamaica's Olympic champion Shelly-Ann Fraser-Price.
Jeter said: "We always want the 'W' [win]. The Worlds is going to be a great race - everyone is running great this year so I need to go fix a couple of things. Nowadays if you're in the final you're capable of winning, so you can't sleep on nobody."
Javier Culson set a season's best as he won the 400m hurdles in 48.33 sec, with former Olympic champion Angelo Taylor disqualified and Britain's Rhys Williams outside the GB qualifying mark with 49.72 sec, in fourth.
"It felt like the weight of my world on my shoulders," said Williams, whose former training partner and current European number one Dai Greene chose to rest rather than compete.
"It's all about aiming towards next year for me now."
Walter Dix of the US produced a storming run to win the 200m in 20.16 sec while his compatriot Leonel Manzano out-kicked Bernard Lagat to win the Emsley Carr Mile
Australian 100m hurdler Sally Pearson continued her brilliant unbeaten run with a storming victory in 12.58 secs to confirm her own status as favourite for World gold, with Britain's Tiffany Ofili-Porter back in third.
Pearson said: "It's been a pretty fantastic season for me. I thought I could have gone a bit faster but it wasn't to be. Winning every single one of my races before the World Championships is a really big confidence booster for me."