C172 pilot reported a near midair collision with another aircraft in cruise flight.

Attributes
ACN	1561893
Time
Date	201807
Local Time Of Day	0601-1200
Place
Locale Reference	FIN.Airport
State Reference	FL
Environment
Flight Conditions	Marginal
Light	Daylight
Aircraft 1
Make Model Name	Skyhawk 172/Cutlass 172
Operating Under FAR Part	Part 91
Flight Phase	Cruise
Route In Use	None
Flight Plan	VFR
Person 1
Function	Single Pilot Pilot Flying
Qualification	Flight Crew Instrument Flight Crew Private
Experience	Flight Crew Last 90 Days 35 Flight Crew Total 140 Flight Crew Type 140
Events
Anomaly	Conflict NMAC Deviation - Track / Heading All Types
Miss Distance	Horizontal 50 Vertical 50

Narrative:

Flying to ZZZ heading to the north at 4500. ATC said aircraft at my 5 o'clock and gaining speed. I turn to the west for a minute so aircraft can pass behind me. When he was no factor turning back to the north I made left hand turn due to cloud build-ups in front of me. About a heading of 060-030 aircraft turned around. ATC told me he made a 180 and said 4000 was clear so I headed nose down instantly and aircraft was on my 9 o'clock. I was already under him but I could see the shine from prop cap and the tires under the wheel fairing. I did avoid the traffic as he passed me over the top. I resumed my flight and landed to no issue.

Original NASA ASRS Text

Title: C172 pilot reported a NMAC with another aircraft in cruise flight.

Narrative: Flying to ZZZ heading to the north at 4500. ATC said aircraft at my 5 o'clock and gaining speed. I turn to the west for a minute so aircraft can pass behind me. When he was no factor turning back to the north I made left hand turn due to cloud build-ups in front of me. About a heading of 060-030 aircraft turned around. ATC told me he made a 180 and said 4000 was clear so I headed nose down instantly and aircraft was on my 9 o'clock. I was already under him but I could see the shine from prop cap and the tires under the wheel fairing. I did avoid the traffic as he passed me over the top. I resumed my flight and landed to no issue.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.